https://docs.pytest.org/en/latest/getting-started.html#create-your-first-test

http://www.testclass.net/pytest

【一】assert & raise

共三个相关文件 test_assert_one.py test_assert_two.py users.dev.json

test_assert_one.py

'''

[basic]

can't has chinese and chinese's symbol,otherwise,the error will run

'''

import pytest

def test_raise1():

with pytest.raises(ZeroDivisionError):

1/0

def test_raise2():

with pytest.raises(ValueError):

2/3

def test_raise3():

with pytest.raises(ZeroDivisionError):

1/2

"""

_________________________________ test_raise2 __________________________________

def test_raise2():

    with pytest.raises(ValueError):

2/3

E Failed: DID NOT RAISE <type 'exceptions.ValueError'>

calc_test.py:12: Failed

_________________________________ test_raise3 __________________________________

def test_raise3():

    with pytest.raises(ZeroDivisionError):

1/2

E Failed: DID NOT RAISE <type 'exceptions.ZeroDivisionError'>

calc_test.py:16: Failed

"""

[visit exception's basic info]

def test_raise4():

with pytest.raises(RuntimeError) as excinfo:

def f():

f()

f()

assert 'maximum2 recursion' in str(excinfo.value)

'''

_____________________________ test_recursion_depth _____________________________

def test_recursion_depth():

    with pytest.raises(RuntimeError) as excinfo:

        def f():

            f()

        f()

  assert 'maximum2 recursion' in str(excinfo.value)

E assert 'maximum2 recursion' in 'maximum recursion depth exceeded'

E + where 'maximum recursion depth exceeded' = str(RuntimeError('maximum recursion depth exceeded',))

E + where RuntimeError('maximum recursion depth exceeded',) = .value

test_one.py:49: AssertionError

'''

custom the exc's message

def test_raise5():

with pytest.raises(ZeroDivisionError,message='expected ZeroDivError!!'):

1/2

'''

___________________________ test_custom_exc_message ____________________________

def test_custom_exc_message():

    with pytest.raises(ZeroDivisionError,message='expected ZeroDivError!!'):

1/2

E Failed: expected ZeroDivError!!

test_one.py:71: Failed

'''

def test_raise6():

a = 10

b = 11

assert a%2 == 0,'value is odd,should be even'

assert b%2 == 0,'value is odd,should be even'

'''

_________________________________ test_raise6 __________________________________

def test_raise6():

    a = 10

    b = 11

    assert a%2 == 0,'value is odd,should be even'

  assert b%2 == 0,'value is odd,should be even'

E AssertionError: value is odd,should be even

E assert (11 % 2) == 0

test_one.py:88: AssertionError

'''

def myfunc():

raise ValueError('Exception 123 raised')

def test_raise7():

with pytest.raises(ValueError,match=r'.* 8888 .*'):

myfunc()

'''

no error , i don't kwow why.....

'''

[Making use of context-sensitive comparisons]

def test_set_comparision():

set1 = set('1308')

set2 = set('8035')

assert set1 == set2

'''

_____________________________ test_set_comparision _____________________________

def test_set_comparision():

    set1 = set('1308')

    set2 = set('8035')

  assert set1 == set2

E assert set(['0', '1', '3', '8']) == set(['0', '3', '5', '8'])

E Extra items in the left set:

E '1'

E Extra items in the right set:

E '5'

E Use -v to get the full diff

test_one.py:122: AssertionError

'''

[Defining your own assertion comparison]

pytest_assertrepr_compare(config, op, left, right)

from test_assert_two import Foo

def pytest_assertrepr_compare(op, left, right):

if isinstance(left, Foo) and isinstance(right, Foo) and op == "==":

return ['Comparing Foo instances:',

' vals: %s != %s' % (left.val, right.val)]

test_assert_two.py

class Foo(object):

def init(self,val):

self.val = val

def __eq__(self, other):

    return self.val == other.val

def test_compare():

f1 = Foo(1)

f2 = Foo(2)

assert f1 == f2

'''

if only do this , result as follow:

_________________________________ test_compare _________________________________

def test_compare():

    f1 = Foo(1)

    f2 = Foo(2)

  assert f1 == f2

E assert <test_two.Foo object at 0x1063a6610> == <test_two.Foo object at 0x1063a6550>

test_two.py:11: AssertionError

if has pytest_assertrepr_compare() ,the result also the up ,don't know why????

but the docs is "

E assert Comparing Foo instances:

E vals: 1 != 2"

'''

users.dev.json

[

{"name":"jack","password":"Iloverose"},

{"name":"rose","password":"Ilovejack"},

{"name":"tom","password":"password123"}

]

【二】 fixture

test_fuxture_one.py 和 contest.py

test_fixture_one.py

coding=utf-8

we have file as 'users.dev.json' in the same directory

"""

import pytest

import json

class TestUserPassword(object):

@pytest.fixture

def users(self):

return json.loads(open('./users.dev.json','r').read())

def test_user_password(self,users):

    for user in users:

        password = user['password']

        assert len(password) >= 6

        msg= 'user %s has a weak password' % user['name']

        assert password != 'password',msg

        assert password != 'password123',msg

'''

pytest test_fixture.py

_____________________ TestUserPassword.test_user_password ______________________

self = <test_fixture_one.TestUserPassword object at 0x10b791f50>

users = [{'name': 'jack', 'password': 'Iloverose'}, {'name': 'rose', 'password': 'Ilovejack'}, {'name': 'tom', 'password': 'password123'}]

def test_user_password(self,users):

    for user in users:

        password = user['password']

        assert len(password) >= 6

        msg= 'user %s has a weak password' % user['name']

        assert password != 'password',msg

      assert password != 'password123',msg

E AssertionError: user tom has a weak password

E assert 'password123' != 'password123'

test_fixture_one.py:18: AssertionError

'''

[Fixtures as Function arguments]

'''

Test functions can receive fixture objects by naming them as an input argument.

For each argument name, a fixture function with that name provides the fixture object.

Fixture functions are registered by marking them with @pytest.fixture.

Let’s look at a simple self-contained test module containing a fixture and a test function using it:

Here, the test_ehlo needs the smtp_connection fixture value.

pytest will discover and call the @pytest.fixture marked smtp_connection fixture function.

'''

import pytest

@pytest.fixture

def smtp_connection():

import smtplib

return smtplib.SMTP("smtp.gmail.com", 586, timeout=5)

def test_ehlo(smtp_connection):

response, msg = smtp_connection.ehlo()

assert response == 250

assert 0 # for demo purposes

'''

surendeMacBook-Air:~/PycharmProjects/liaoxuefeng_test1/888 suren$pytest test_fixture_one.py

============================= test session starts ==============================

platform darwin -- Python 2.7.13, pytest-3.0.5, py-1.4.32, pluggy-0.4.0

rootdir: /Users/suren/PycharmProjects/liaoxuefeng_test1/888, inifile:

collected 2 items

test_fixture_one.py FE

==================================== ERRORS ====================================

_________________________ ERROR at setup of test_ehlo __________________________

@pytest.fixture

def smtp_connection():

    import smtplib

  return smtplib.SMTP("smtp.gmail.com", 586, timeout=5)

test_fixture_one.py:48:

../../../ST/anaconda/anaconda/lib/python2.7/smtplib.py:256: in init

(code, msg) = self.connect(host, port)

../../../ST/anaconda/anaconda/lib/python2.7/smtplib.py:316: in connect

self.sock = self._get_socket(host, port, self.timeout)

../../../ST/anaconda/anaconda/lib/python2.7/smtplib.py:291: in _get_socket

return socket.create_connection((host, port), timeout)

address = ('smtp.gmail.com', 586), timeout = 5, source_address = None

def create_connection(address, timeout=_GLOBAL_DEFAULT_TIMEOUT,

                      source_address=None):

    #Connect to *address* and return the socket object.

    #Convenience function.  Connect to *address* (a 2-tuple (host,

    #port)) and return the socket object.  Passing the optional

    #*timeout* parameter will set the timeout on the socket instance

    #before attempting to connect.  If no *timeout* is supplied, the

    #global default timeout setting returned by :func:`getdefaulttimeout`

    #is used.  If *source_address* is set it must be a tuple of (host, port)

    #for the socket to bind as a source address before making the connection.

    #A host of '' or port 0 tells the OS to use the default.

    #'''

    host, port = address

    err = None

    for res in getaddrinfo(host, port, 0, SOCK_STREAM):

        af, socktype, proto, canonname, sa = res

        sock = None

        try:

            sock = socket(af, socktype, proto)

            if timeout is not _GLOBAL_DEFAULT_TIMEOUT:

                sock.settimeout(timeout)

            if source_address:

                sock.bind(source_address)

            sock.connect(sa)

            return sock

        except error as _:

            err = _

            if sock is not None:

                sock.close()

    if err is not None:

      raise err

E error: [Errno 65] No route to host

../../../ST/anaconda/anaconda/lib/python2.7/socket.py:575: error

'''

import pytest

@pytest.fixture

def smtp_conn2():

import smtplib

return smtplib.SMTP('smtp.gmail.com',587,timeout=5)

def test_ehlo2(smtp_conn2):

response,msg = smtp_conn2.ehlo()

assert response == 250

'''

surendeMacBook-Air:~/PycharmProjects/liaoxuefeng_test1/888 suren$pytest test_fixture_one.py

============================= test session starts ==============================

platform darwin -- Python 2.7.13, pytest-3.0.5, py-1.4.32, pluggy-0.4.0

rootdir: /Users/suren/PycharmProjects/liaoxuefeng_test1/888, inifile:

collected 1 items

test_fixture_one.py .

=========================== 1 passed in 5.86 seconds ===========================

'''

import pytest

@pytest.fixture

def smtp_conn3():

import smtplib

return smtplib.SMTP('smtp.gmail.com',587,timeout=5)

def test_ehlo3(smtp_conn3):

response ,msg = smtp_conn3.ehlo()

assert response == 250

assert 0

test_fixture_one.py F

=================================== FAILURES ===================================

__________________________________ test_ehlo3 __________________________________

smtp_conn3 = <smtplib.SMTP instance at 0x10e3fe488>

def test_ehlo3(smtp_conn3):

    response ,msg = smtp_conn3.ehlo()

    assert response == 250

  assert 0

E assert 0

test_fixture_one.py:161: AssertionError

=========================== 1 failed in 5.90 seconds ===========================

[tips]

Note

You can always issue

pytest --fixtures test_simplefactory.py

to see available fixtures (fixtures with leading _ are only shown if you add the -v option).

'''

'''

surendeMacBook-Air:~/PycharmProjects/liaoxuefeng_test1/888 suren$pytest --fixtures test_fixture_one.py

============================= test session starts ==============================

platform darwin -- Python 2.7.13, pytest-3.0.5, py-1.4.32, pluggy-0.4.0

rootdir: /Users/suren/PycharmProjects/liaoxuefeng_test1/888, inifile:

collected 1 items

cache

Return a cache object that can persist state between testing sessions.

cache.get(key, default)

cache.set(key, value)

Keys must be a ``/`` separated value, where the first part is usually the

name of your plugin or application to avoid *es with other cache users.

Values can be any object handled by the json stdlib module.

capsys

Enable capturing of writes to sys.stdout/sys.stderr and make

captured output available via capsys.readouterr() method calls

which return a (out, err) tuple.

capfd

Enable capturing of writes to file descriptors 1 and 2 and make

captured output available via capfd.readouterr() method calls

which return a (out, err) tuple.

doctest_namespace

Inject names into the doctest namespace.

pytestconfig

the pytest config object with access to command line opts.

record_xml_property

Add extra xml properties to the tag for the calling test.

The fixture is callable with (name, value), with value being automatically

xml-encoded.

monkeypatch

The returned monkeypatch fixture provides these

helper methods to modify objects, dictionaries or os.environ::

monkeypatch.setattr(obj, name, value, raising=True)

monkeypatch.delattr(obj, name, raising=True)

monkeypatch.setitem(mapping, name, value)

monkeypatch.delitem(obj, name, raising=True)

monkeypatch.setenv(name, value, prepend=False)

monkeypatch.delenv(name, value, raising=True)

monkeypatch.syspath_prepend(path)

monkeypatch.chdir(path)

All modifications will be undone after the requesting

test function or fixture has finished. The ``raising``

parameter determines if a KeyError or AttributeError

will be raised if the set/deletion operation has no target.

recwarn

Return a WarningsRecorder instance that provides these methods:

* ``pop(category=None)``: return last warning matching the category.

* ``clear()``: clear list of warnings

See http://docs.python.org/library/warnings.html for information

on warning categories.

tmpdir_factory

Return a TempdirFactory instance for the test session.

tmpdir

Return a temporary directory path object

which is unique to each test function invocation,

created as a sub directory of the base temporary

directory. The returned object is a py.path.local_

path object.

-------------------- fixtures defined from test_fixture_one --------------------

smtp_conn3

test_fixture_one.py:169: no docstring available

'''

例子 conftest.py 和当前文件在同一目录下

def test_conn5(smtp_conn):

response,msg = smtp_conn.ehlo()

assert response == 250

test_fixture_one.py .

=========================== 1 passed in 5.93 seconds ===========================

'''

例子 conftest.py 和当前文件不在同一目录下

def test_conn5(smtp_conn):

response,msg = smtp_conn.ehlo()

assert response == 250

assert 0

'''

============================= test session starts ==============================

platform darwin -- Python 2.7.13, pytest-3.0.5, py-1.4.32, pluggy-0.4.0

rootdir: /Users/suren/PycharmProjects/liaoxuefeng_test1/888, inifile:

collected 1 items

test_fixture_one.py F

=================================== FAILURES ===================================

__________________________________ test_conn5 __________________________________

smtp_conn = <smtplib.SMTP instance at 0x10578e3f8>

def test_conn5(smtp_conn):

    response,msg = smtp_conn.ehlo()

    assert response == 250

  assert 0

E assert 0

test_fixture_one.py:312: AssertionError

=========================== 1 failed in 5.76 seconds ===========================

'''

例子 conftest.py 不叫这个名字，换个 conftest1.py

def test_conn5(smtp_conn):

response,msg = smtp_conn.ehlo()

assert response == 250

'''

========================== 1 failed in 5.76 seconds ===========================

surendeMacBook-Air:~/PycharmProjects/liaoxuefeng_test1/888 suren$pytest test_fixture_one.py

============================= test session starts ==============================

platform darwin -- Python 2.7.13, pytest-3.0.5, py-1.4.32, pluggy-0.4.0

rootdir: /Users/suren/PycharmProjects/liaoxuefeng_test1/888, inifile:

collected 1 items

test_fixture_one.py E

==================================== ERRORS ====================================

_________________________ ERROR at setup of test_conn5 _________________________

file /Users/suren/PycharmProjects/liaoxuefeng_test1/888/test_fixture_one.py, line 341

def test_conn5(smtp_conn):

E fixture 'smtp_conn' not found

  available fixtures: cache, capfd, capsys, doctest_namespace, monkeypatch, pytestconfig, record_xml_property, recwarn, tmpdir, tmpdir_factory

  use 'pytest --fixtures [testpath]' for help on them.

/Users/suren/PycharmProjects/liaoxuefeng_test1/888/test_fixture_one.py:341

=========================== 1 error in 0.01 seconds ============================

'''

"""

conftest.py

import pytest

@pytest.fixture

def smtp_conn():

import smtplib

return smtplib.SMTP('smtp.gmail.com',587,timeout=5)

"""

例子 test_fixture_one.py在外部，conftest.py在与test_fixture_one.py同目录的文件夹内部

def test_ehlo(smtp_conn):

response,msg = smtp_conn.ehlo()

assert response == 250

assert b'smtp.gmail.com' in msg

assert 0

'''

C:/Users/rq/PycharmProjects/untitled>pytest test_fixture_one.py

============================= test session starts =============================

platform win32 -- Python 3.7.0, pytest-3.4.0, py-1.7.0, pluggy-0.6.0

rootdir: C:/Users/rq/PycharmProjects/untitled, inifile:

plugins: xdist-1.22.0, rerunfailures-4.1, metadata-1.7.0, html-1.16.1, forked-0.2

collected 1 item

test_fixture_one.py E [100%]

=================================== ERRORS ====================================

________________________ ERROR at setup of test_conn6 _________________________

file C:/Users/rq/PycharmProjects/untitled/test_fixture_one.py, line 4

def test_conn6(smtp_conn):

E fixture 'smtp_conn' not found

  available fixtures: cache, capfd, capfdbinary, caplog, capsys, capsysbinary, doctest_namespace, metadata, monkeypatch, pytestconfig, record_xml_attribute, record_xml_property, recwarn, tmpdir, tmpdir_factory, worker_id

  use 'pytest --fixtures [testpath]' for help on them.

C:/Users/rq/PycharmProjects/untitled/test_fixture_one.py:4

=========================== 1 error in 0.02 seconds ===========================

'''

【Scope: sharing a fixture instance across tests in a class, module or session】

例子

def test_ehlo(smtp_conn):

response,msg = smtp_conn.ehlo()

assert response == 250

assert b'smtp.gmail.com' in msg

assert 0

def test_noop(smtp_conn):

response,msg = smtp_conn.noop()

assert response == 250

assert 0

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest test_one.py

============================= test session starts =============================

platform win32 -- Python 3.7.0, pytest-3.4.0, py-1.7.0, pluggy-0.6.0

rootdir: C:/Users/rq/PycharmProjects/untitled/test1, inifile:

plugins: xdist-1.22.0, rerunfailures-4.1, metadata-1.7.0, html-1.16.1, forked-0.2

collected 2 items

test_one.py FF [100%]

================================== FAILURES ===================================

__________________________________ test_ehlo __________________________________

smtp_conn = <smtplib.SMTP object at 0x00000224E9266B70>

def test_ehlo(smtp_conn):

    response,msg = smtp_conn.ehlo()

    assert response == 250

    assert b'smtp.gmail.com' in msg

  assert 0

E assert 0

test_one.py:8: AssertionError

__________________________________ test_noop __________________________________

smtp_conn = <smtplib.SMTP object at 0x00000224E92EAA90>

def test_noop(smtp_conn):

    response,msg = smtp_conn.noop()

    assert response == 250

  assert 0

E assert 0

test_one.py:13: AssertionError

========================== 2 failed in 1.36 seconds ===========================

'''

例子如果拼错一个函数参数或想使用一个不可用的函数参数，将会看到一个包含可用函数参数列表的错误。我们可以使用以下命令看到可用的fixture：

pytest --fixtures test_simplefactory.py

def test_ehlo(smtp_conn1):

response, msg = smtp_conn1.ehlo()

assert response == 250

assert 0

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest test_one.py

============================= test session starts =============================

platform win32 -- Python 3.7.0, pytest-3.4.0, py-1.7.0, pluggy-0.6.0

rootdir: C:/Users/rq/PycharmProjects/untitled/test1, inifile:

plugins: xdist-1.22.0, rerunfailures-4.1, metadata-1.7.0, html-1.16.1, forked-0.2

collected 1 item

test_one.py E [100%]

=================================== ERRORS ====================================

_________________________ ERROR at setup of test_ehlo _________________________

file C:/Users/rq/PycharmProjects/untitled/test1/test_one.py, line 87

def test_ehlo(smtp_conn1):

E fixture 'smtp_conn1' not found

  available fixtures: cache, capfd, capfdbinary, caplog, capsys, capsysbinary, doctest_namespace, metadata, monkeypatch, pytestconfig, record_xml_attribute, record_xml_property, recwarn, smtp_conn, tmpdir, tmpdir_factory, w

orker_id

  use 'pytest --fixtures [testpath]' for help on them.

C:/Users/rq/PycharmProjects/untitled/test1/test_one.py:87

=========================== 1 error in 0.02 seconds ===========================

'''

例子 @pytest.fixture(scope='module')

'''

[conftest.py]

import pytest

@pytest.fixture(scope='module')

def smtp_conn():

import smtplib

return smtplib.SMTP('smtp.gmail.com',587,timeout=5)

'''

def test_ehlo(smtp_conn):

response,msg = smtp_conn.ehlo()

assert response == 250

assert b'smtp.gmail.com' in msg

assert 0

def test_noop(smtp_conn):

response,msg = smtp_conn.noop()

assert response == 250

assert 0

test_one.py FF [100%]

================================== FAILURES ===================================

__________________________________ test_ehlo __________________________________

smtp_conn = <smtplib.SMTP object at 0x00000154E03D3B70>

def test_ehlo(smtp_conn):

    response,msg = smtp_conn.ehlo()

    assert response == 250

    assert b'smtp.gmail.com' in msg

  assert 0

E assert 0

test_one.py:134: AssertionError

__________________________________ test_noop __________________________________

smtp_conn = <smtplib.SMTP object at 0x00000154E03D3B70>

def test_noop(smtp_conn):

    response,msg = smtp_conn.noop()

    assert response == 250

  assert 0

E assert 0

test_one.py:139: AssertionError

========================== 2 failed in 0.98 seconds ===========================

【分析】我们可以看到两个assert 0失败，更重要的是，我们也可以看到同一模块范围内的smtp对象被传递到两个测试函数中，

因为pytest显示了回溯中的传入参数值。因此，使用smtp的两个测试函数的运行速度与单个测试函数一样快，因为它们重用了相同的实例。

'''

例子

'''

同目录下conftest.py

import pytest

@pytest.fixture(scope='module')

def smtp_conn():

import smtplib

return smtplib.SMTP('smtp.gmail.com',587,timeout=5)

同目录下还有个文件test_two.py

def test_noop(smtp_conn):

resp,msg = smtp_conn.noop()

assert resp == 250

执行：pytest -s -v

'''

def test_ehlo(smtp_conn):

resp,msg = smtp_conn.ehlo()

assert resp == 250

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest -s -v

======================================================================================================= test session starts ========================================================================================================

platform win32 -- Python 3.7.0, pytest-3.4.0, py-1.7.0, pluggy-0.6.0 -- c:/users/rq/appdata/local/programs/python/python37/python.exe

cachedir: .pytest_cache

metadata: {'Python': '3.7.0', 'Platform': 'Windows-10-10.0.17134-SP0', 'Packages': {'pytest': '3.4.0', 'py': '1.7.0', 'pluggy': '0.6.0'}, 'Plugins': {'xdist': '1.22.0', 'rerunfailures': '4.1', 'metadata': '1.7.0', 'html': '1.16.1

', 'forked': '0.2'}, 'JAVA_HOME': 'C://Program Files//Java//jdk1.8.0_181'}

rootdir: C:/Users/rq/PycharmProjects/untitled/test1, inifile:

plugins: xdist-1.22.0, rerunfailures-4.1, metadata-1.7.0, html-1.16.1, forked-0.2

collected 2 items

test_one.py::test_ehlo PASSED

test_two.py::test_noop PASSED

===================================================================================================== 2 passed in 3.24 seconds =====================================================================================================

'''

例子 scope='session'运行结果同上

def test_ehlo(smtp_conn):

resp,msg = smtp_conn.ehlo()

assert resp == 250

例子 fixture的完成与拆卸代码

'''当fixture超出范围时候，pytest支持执行fixture特定的最终代码，通过使用yield而不是return，yield语句之后的所有代码都用做拆卸代码

[conftest.py]

import pytest

import smtplib

@pytest.fixture(scope='module')

def smtp_conn():

smtp = smtplib.SMTP('smtp.gmail.com',587,timeout=5)

yield smtp

print ('拆卸smtp')

smtp.close()

[test_two.py]

def test_noop(smtp_conn):

resp,msg = smtp_conn.noop()

assert resp == 250

'''

def test_noop(smtp_conn):

resp,msg = smtp_conn.noop()

assert resp == 250

def test_ehlo(smtp_conn):

resp,msg = smtp_conn.ehlo()

assert resp == 250

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest -s -q --tb=no

..拆卸smtp

.拆卸smtp

3 passed in 1.55 seconds

'''

例子没有test_two.py fixture完成与拆卸代码

'''

[conftest.py]

import pytest

import smtplib

@pytest.fixture(scope='module')

def smtp_conn():

smtp = smtplib.SMTP('smtp.gmail.com',587,timeout=5)

yield smtp

print ('拆卸smtp')

smtp.close()

'''

def test_noop(smtp_conn):

resp,msg = smtp_conn.noop()

assert resp == 250

def test_ehlo(smtp_conn):

resp,msg = smtp_conn.ehlo()

assert resp == 250

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest -s -q --tb=no

..拆卸smtp

2 passed in 0.67 seconds

'''

'''

 C:/Users/rq/PycharmProjects/untitled/test1>pytest -q --tb=no

 ..                                                                       [100%]

 2 passed in 0.82 seconds

'''

例子 scope='function'

'''

[conftest.py]

import pytest

import smtplib

@pytest.fixture(scope='function')

def smtp_conn():

smtp = smtplib.SMTP('smtp.gmail.com',587,timeout=5)

yield smtp

print ('拆卸smtp')

smtp.close()

'''

def test_noop(smtp_conn):

resp,msg = smtp_conn.noop()

assert resp == 250

def test_ehlo(smtp_conn):

resp,msg = smtp_conn.ehlo()

assert resp == 250

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest -s -q --tb=no

.拆卸smtp

.拆卸smtp

2 passed in 2.65 seconds

'''

例子我们可通过with语句无缝使用yield语法，这样测试完成后，smtp连接被关闭，因为当with语句结束时，smtp对象会自动关闭

'''

[conftest.py]

import pytest

import smtplib

@pytest.fixture(scope='module')

def smtp_conn():

with smtplib.SMTP('smtp.gmail.com',587,timeout=5) as smtp_conn:

yield smtp_conn

print ('拆卸代码')

'''

def test_noop(smtp_conn):

resp,msg = smtp_conn.noop()

assert resp == 250

def test_ehlo(smtp_conn):

resp,msg = smtp_conn.ehlo()

assert resp == 250

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest -s -q --tb=no

..拆卸代码

2 passed in 0.96 seconds

'''

例子如果在设置代码，即yield关键字之前，期间发生异常，则不会调用拆卸代码，即即yield关键字之后的代码

'''

[conftest.py]

import pytest

import smtplib

@pytest.fixture(scope='module')

def smtp_conn():

with smtplib.SMTP('smtp.gmail.com',587,timeout=5) as smtp_conn:

yield smtp_conn

raise ValueError

print ('拆卸代码')

'''

def test_noop(smtp_conn):

resp,msg = smtp_conn.noop()

assert resp == 250

def test_ehlo(smtp_conn):

resp,msg = smtp_conn.ehlo()

assert resp == 250

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest -s -q --tb=no

..E

2 passed, 1 error in 1.31 seconds

'''

例子执行拆卸代码的另一种方式是利用请求上下文对象的addfinalizer方法来注册完成函数。

'''

[conftest.py]

import pytest

import smtplib

@pytest.fixture(scope='module')

def smtp_conn(request):

smtp = smtplib.SMTP('smtp.gmail.com',587,timeout=5)

def fin():

print ('拆卸代码')

smtp.close()

request.addfinalizer(fin)

return smtp

'''

def test_noop(smtp_conn):

resp,msg = smtp_conn.noop()

assert resp == 250

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest -s -q --tb=no

.拆卸代码

1 passed in 0.73 seconds

'''

'''

yield和addfinalizer方法在测试结束后通过调用它们的代码来工作，但addfinalizer与yield相比有两个关键的区别。第一点是，可以注册多个完成函数。第二点是，无论fixture设置代码是否引发异常，完成函数将始终被调用，即使其中一个未能创建与获取，也可以正确关闭由fixture创建的所有资源：

@pytest.fixture

def equipments(request):

r = []

for port in ('C1', 'C3', 'C28'):

equip = connect(port)

request.addfinalizer(equip.disconnect)

r.append(equip)

return r

在上面的代码中，如果“C28”发生异常，“C1”和“C3”仍然会被正确关闭。当然，如果在完成函数注册之前发生异常，那么它将不会被执行。

'''

"""

coding=utf-8

"""

例子 fixture反向获取请求的测试环境

'''

fixture函数可以通过接收request对象来反向获取请求中的测试函数、类或模块上下文，进一步扩展之前的smtp fixture

示例，让我们从fixture的测试模块读取可选的服务器URL

[conftest.py]

coding=utf-8

import pytest

import smtplib

@pytest.fixture(scope='module')

def smtp(request):

server = getattr(request.module,'smtpserver','smtp.qq.com')

smtp = smtplib.SMTP(server,587,timeout=5)

yield smtp

print ('完成 %s(%s) % (smtp,server)')

smtp.close()

'''

def test_elho(smtp):

resp, msg = smtp.ehlo()

assert resp == 250

'''

surendeMacBook-Air:~/PycharmProjects/liaoxuefeng_test1/888 suren$pytest -s -q --tb=no

.完成 <smtplib.SMTP instance at 0x10ac34200>(smtp.qq.com)

1 passed in 5.15 seconds

'''

例子再让我们快速创建另一个测试模块，在其模块名称空间中实际设置服务器URL，

'''

新建一个test_anothersmtp.py文件，输入以下代码：

coding=utf-8

smtpserver = 'mail.python.org'

def test_showehlo(smtp):

assert 0,smtp.ehlo()

[conftest.py]

coding=utf-8

import pytest

import smtplib

执行结果：

surendeMacBook-Air:~/PycharmProjects/liaoxuefeng_test1/888 suren$pytest -qq --tb=short test_assert_one.py

F

=================================== FAILURES ===================================

________________________________ test_showehlo _________________________________

test_assert_one.py:6: in test_showehlo

assert 0,smtp.ehlo()

E AssertionError: (250, 'mail.python.org

E PIPELINING

E SIZE 51200000

E ETRN

E STARTTLS

E AUTH DIGEST-MD5 NTLM CRAM-MD5

E ENHANCEDSTATUSCODES

E 8BITMIME

E DSN

E SMTPUTF8

E CHUNKING')

E assert 0

--------------------------- Captured stdout teardown ---------------------------

完成 <smtplib.SMTP instance at 0x1086138c0>(mail.python.org)

'''

例子参数化fixture

'''

fixture函数可以参数化，在这种情况下，它们将被多次调用，每次执行一组相关测试

即依赖于这个fixture的测试，测试函数通常不需要知道它们的重新运行。

fixture参数化可以用于一些有多种方式配置的功能测试。

扩展前面的例子，我们可以标记fixture来创建两个smtp fixture实例，

这将导致使用fixture的所有测试运行两次，fixture函数通过特殊的request对象访问每个参数：

[conftest.py]

coding=utf-8

import pytest

import smtplib

@pytest.fixture(scope='module',params=['smtp.qq.com','mail.python.org'])

def smtp(request):

smtp = smtplib.SMTP(request.param,587,timeout=5)

yield smtp

print ('完成 %s' % smtp)

smtp.close()

'''

def test_ehlo(smtp):

resp,msg = smtp.ehlo()

assert resp == 250

assert b'smtp.qq.com' in msg

def test_noop(smtp):

resp,msg = smtp.noop()

assert resp == 250

assert b'smtp.qq.com' in msg

'''

surendeMacBook-Air:~/PycharmProjects/liaoxuefeng_test1/888 suren$pytest -q test_fixture_one.py

.FFF

=================================== FAILURES ===================================

____________________________ test_noop[smtp.qq.com] ____________________________

smtp = <smtplib.SMTP instance at 0x10b8ea5a8>

def test_noop(smtp):

    resp,msg = smtp.noop()

  assert resp == 250

E assert 530 == 250

test_fixture_one.py:109: AssertionError

__________________________ test_ehlo[mail.python.org] __________________________

smtp = <smtplib.SMTP instance at 0x10b8ea9e0>

def test_ehlo(smtp):

    resp,msg = smtp.ehlo()

    assert resp == 250

  assert b'smtp.qq.com' in msg

E assert 'smtp.qq.com' in 'mail.python.org\nPIPELINING\nSIZE 51200000\nETRN\nSTARTTLS\nAUTH DIGEST-MD5 NTLM CRAM-MD5\nENHANCEDSTATUSCODES\n8BITMIME\nDSN\nSMTPUTF8\nCHUNKING'

test_fixture_one.py:105: AssertionError

---------------------------- Captured stdout setup -----------------------------

完成 <smtplib.SMTP instance at 0x10b8ea5a8>

__________________________ test_noop[mail.python.org] __________________________

smtp = <smtplib.SMTP instance at 0x10b8ea9e0>

def test_noop(smtp):

    resp,msg = smtp.noop()

    assert resp == 250

  assert b'smtp.qq.com' in msg

E assert 'smtp.qq.com' in '2.0.0 Ok'

test_fixture_one.py:110: AssertionError

--------------------------- Captured stdout teardown ---------------------------

完成 <smtplib.SMTP instance at 0x10b8ea9e0>

3 failed, 1 passed in 11.15 seconds

'''

例子

'''

[conftest.py]

coding=utf-8

import pytest

import smtplib

@pytest.fixture(scope='module')

def smtp():

smtp = smtplib.SMTP('smtp.gmail.com',587,timeout=5)

yield smtp

print ('完成 %s' % smtp)

smtp.close()

'''

def test_ehlo(smtp):

resp,msg = smtp.ehlo()

assert resp == 250

assert b'smtp.qq.com' in msg

def test_noop(smtp):

resp,msg = smtp.noop()

assert resp == 250

assert b'smtp.qq.com' in msg

'''

surendeMacBook-Air:~/PycharmProjects/liaoxuefeng_test1/888 suren$pytest -q test_fixture_one.py

FF

=================================== FAILURES ===================================

__________________________________ test_ehlo ___________________________________

smtp = <smtplib.SMTP instance at 0x107c8ed88>

def test_ehlo(smtp):

    resp,msg = smtp.ehlo()

    assert resp == 250

  assert b'smtp.qq.com' in msg

E assert 'smtp.qq.com' in 'smtp.gmail.com at your service, [180.157.84.37]\nSIZE 35882577\n8BITMIME\nSTARTTLS\nENHANCEDSTATUSCODES\nPIPELINING\nCHUNKING\nSMTPUTF8'

test_fixture_one.py:105: AssertionError

__________________________________ test_noop ___________________________________

smtp = <smtplib.SMTP instance at 0x107c8ed88>

def test_noop(smtp):

    resp,msg = smtp.noop()

    assert resp == 250

  assert b'smtp.qq.com' in msg

E assert 'smtp.qq.com' in '2.0.0 OK h64sm24958677pfc.142 - gsmtp'

test_fixture_one.py:110: AssertionError

--------------------------- Captured stdout teardown ---------------------------

完成 <smtplib.SMTP instance at 0x107c8ed88>

2 failed in 6.08 seconds

'''

"""

encoding=utf-8

'''

我们可以看到，我们的两个测试函数每个都运行了两次，而且是针对不同的smtp实例。pytest将建立一个字符串，它是参数化fixture中每个fixture值的测试ID，在上面的例子中，test_ehlo[smtp.qq.com]和test_ehlo[mail.python.org]，这些ID可以与-k一起使用来选择要运行的特定实例，还可以在发生故障时识别特定实例。使用--collect-only运行pytest会显示生成的ID。

数字、字符串、布尔值和None将在测试ID中使用其通常的字符串表示形式，对于其他对象，pytest会根据参数名称创建一个字符串，可以通过使用ids关键字参数来自定义用于测试ID的字符串。新建一个test_ids.py文件，输入以下代码：

ids可以是一个要使用的字符串列表，还可以是一个将用fixture值调用的函数，然后返回一个字符串来使用。在后一种情况下，如果函数返回None，那么将使用pytest的自动生成的ID

'''

例子

"""

import pytest

@pytest.fixture(params=[2,5],ids=['spam','ham'])

def a(request):

return request.param

def test_a(a):

pass

def idfn(fixture_value):

if fixture_value == 5:

return 'eggs'

else:

return None

@pytest.fixture(params=[7,5],ids=idfn)

def b(request):

return request.param

def test_b(b):

pass

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest --collect-only

============================= test session starts =============================

platform win32 -- Python 3.7.0, pytest-3.4.0, py-1.7.0, pluggy-0.6.0

rootdir: C:/Users/rq/PycharmProjects/untitled/test1, inifile:

plugins: xdist-1.22.0, rerunfailures-4.1, metadata-1.7.0, html-1.16.1, forked-0.2

collected 4 items

<Module 'test_one.py'>

<Function 'test_a[spam]'>

<Function 'test_a[ham]'>

<Function 'test_b[7]'>

<Function 'test_b[eggs]'>

======================== no tests ran in 0.02 seconds =========================

'''

例子

import pytest

@pytest.fixture(params=[0,1],ids=['spam','ham'])

def a(request):

return request.param

def test_a(a):

pass

def idfn(fixture_val):

if fixture_val == 1:

return 'eggs'

else:

return None

@pytest.fixture(params=[1,0],ids=idfn)

def b(request):

return request.param

def test_b(b):

pass

======================== no tests ran in 0.02 seconds =========================

'''

例子

import pytest

@pytest.fixture(ids=['spam','ham'])

def a(request):

return request.param

def test_a(a):

pass

def idfn(val):

if val == 9:

return 'eggs'

else:

return None

@pytest.fixture(params=[3,9],ids=idfn)

def b(request):

return request.param

def test_b(b):

pass

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest --collect-only

============================= test session starts =============================

platform win32 -- Python 3.7.0, pytest-3.4.0, py-1.7.0, pluggy-0.6.0

rootdir: C:/Users/rq/PycharmProjects/untitled/test1, inifile:

plugins: xdist-1.22.0, rerunfailures-4.1, metadata-1.7.0, html-1.16.1, forked-0.2

collected 3 items

<Module 'test_one.py'>

<Function 'test_a'>

<Function 'test_b[3]'>

<Function 'test_b[eggs]'>

======================== no tests ran in 0.02 seconds =========================

'''

例子

import pytest

@pytest.fixture(ids=['spam','ham'])

def a(request):

return 22

def test_a(a):

assert a == 22

def idfn(val):

if val == 9:

return 'eggs'

else:

return None

@pytest.fixture(params=[3,9],ids=idfn)

def b(request):

print (request.param)

return request.param

def test_b(b):

assert b in (1,9)

test_one.py .F. [100%]

================================== FAILURES ===================================

__________________________________ test_b[3] __________________________________

b = 3

def test_b(b):

  assert b in (1,9)

E assert 3 in (1, 9)

test_one.py:157: AssertionError

---------------------------- Captured stdout setup ----------------------------

3

===================== 1 failed, 2 passed in 0.05 seconds ======================

'''

例子使用fixture函数的fixture

'''

我们不仅可以在测试函数中使用fixture，而且fixture函数也可以使用其他fixture，这有助于fixture的模块化设计，

并允许在许多项目中重新使用框架特定的fixture。例如，我们可以扩展前面的例子，并实例化一个app对象

[conftest.py]

import pytest

import smtplib

@pytest.fixture(scope='module')

def smtp():

smtp = smtplib.SMTP('smtp.qq.com',587,timeout=5)

return smtp

'''

import pytest

class App(object):

def init(self,smtp):

self.smtp = smtp

@pytest.fixture(scope='module')

def app(smtp):

return App(smtp)

def test_smtp_exists(app):

assert app.smtp

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest -v test_one.py

============================= test session starts =============================

platform win32 -- Python 3.7.0, pytest-3.4.0, py-1.7.0, pluggy-0.6.0 -- c:/users/rq/appdata/local/programs/python/python37/python.exe

cachedir: .pytest_cache

metadata: {'Python': '3.7.0', 'Platform': 'Windows-10-10.0.17134-SP0', 'Packages': {'pytest': '3.4.0', 'py': '1.7.0', 'pluggy': '0.6.0'}, 'Plugins': {'xdist': '1.22.0', 'rerunfailures': '4.1', 'metadata': '1.7.0', 'html': '1.16.1

', 'forked': '0.2'}, 'JAVA_HOME': 'C://Program Files//Java//jdk1.8.0_181'}

rootdir: C:/Users/rq/PycharmProjects/untitled/test1, inifile:

plugins: xdist-1.22.0, rerunfailures-4.1, metadata-1.7.0, html-1.16.1, forked-0.2

collected 1 item

test_one.py::test_smtp_exists PASSED [100%]

========================== 1 passed in 0.09 seconds ===========================

'''

例子通过fixture实例自动分组测试

'''

pytest在测试运行期间会最小化活动fixture的数量，如果我们有一个参数化的fixture，那么所有使用它的测试将首先执行一个实例，然后在下一个fixture实例被创建之前调用终结器。

'''

import pytest

@pytest.fixture(scope='module',params=['mod1','mod2'])

def modarg(request):

param = request.param

print (' 设置 modarg %s' % param)

yield param

print (' 拆卸 modarg %s' % param)

@pytest.fixture(scope='function',params=[1,2])

def otherarg(request):

param = request.param

print (' 设置 otherarg %s' % param)

yield param

print (' 拆卸 otherarg %s' % param)

def test_0(otherarg):

print (' 用 otherarg %s 运行 test0' % otherarg)

def test_1(modarg):

print (' 用 modarg %s 运行 test1' % modarg)

def test_2(otherarg,modarg):

print (' 用 otherarg %s 和 modarg %s 运行 test2' % (otherarg,modarg))

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest -v -s test_one.py

======================================================================================================= test session starts ========================================================================================================

platform win32 -- Python 3.7.0, pytest-3.4.0, py-1.7.0, pluggy-0.6.0 -- c:/users/rq/appdata/local/programs/python/python37/python.exe

cachedir: .pytest_cache

metadata: {'Python': '3.7.0', 'Platform': 'Windows-10-10.0.17134-SP0', 'Packages': {'pytest': '3.4.0', 'py': '1.7.0', 'pluggy': '0.6.0'}, 'Plugins': {'xdist': '1.22.0', 'rerunfailures': '4.1', 'metadata': '1.7.0', 'html': '1.16.1

', 'forked': '0.2'}, 'JAVA_HOME': 'C://Program Files//Java//jdk1.8.0_181'}

rootdir: C:/Users/rq/PycharmProjects/untitled/test1, inifile:

plugins: xdist-1.22.0, rerunfailures-4.1, metadata-1.7.0, html-1.16.1, forked-0.2

collected 8 items

test_one.py::test_0[1] 设置 otherarg 1

用 otherarg 1 运行 test0

PASSED 拆卸 otherarg 1

test_one.py::test_0[2] 设置 otherarg 2

用 otherarg 2 运行 test0

PASSED 拆卸 otherarg 2

test_one.py::test_1[mod1] 设置 modarg mod1

用 modarg mod1 运行 test1

PASSED

test_one.py::test_2[1-mod1] 设置 otherarg 1

用 otherarg 1 和 modarg mod1 运行 test2

PASSED 拆卸 otherarg 1

test_one.py::test_2[2-mod1] 设置 otherarg 2

用 otherarg 2 和 modarg mod1 运行 test2

PASSED 拆卸 otherarg 2

test_one.py::test_1[mod2] 拆卸 modarg mod1

设置 modarg mod2

用 modarg mod2 运行 test1

PASSED

test_one.py::test_2[1-mod2] 设置 otherarg 1

用 otherarg 1 和 modarg mod2 运行 test2

PASSED 拆卸 otherarg 1

test_one.py::test_2[2-mod2] 设置 otherarg 2

用 otherarg 2 和 modarg mod2 运行 test2

PASSED 拆卸 otherarg 2

拆卸 modarg mod2

===================================================================================================== 8 passed in 0.03 seconds =====================================================================================================

[解析]

我们可以看到参数化的module（模块）范围的modarg资源影响了测试执行的排序，使用了最少的活动资源。

mod1参数化资源的终结器是在mod2资源建立之前执行的。特别要注意test_0是完全独立的，会首先完成，

然后用mod1执行test_1，再然后用mod1执行test_2，再然后用mod2执行test_1，最后用mod2执行test_2。otherarg参数化资源是function（函数）的范围，是在每次使用测试之后建立起来的。

'''

例子使用类、模块或项目的fixture

'''

有时测试函数不需要直接访问一个fixture对象，例如，测试可能需要使用空目录作为当前工作目录，不关心具体目录。这里使用标准的tempfile和pytest fixture来实现它，我们将fixture的创建分隔成一个conftest.py文件：

import pytest

import tempfile

import os

@pytest.fixture()

def cleandir():

newpath = tempfile.mkdtemp()

os.chdir(newpath)

'''

import os

import pytest

@pytest.mark.usefixtures('cleandir')

class TestDirectoryInit(object):

def test_cwd_starts_empty(self):

assert os.listdir(os.getcwd()) == []

with open('myfile','w') as f:

f.write('hello')

def test_cwd_again_starts_empty(self):

    assert os.listdir(os.getcwd()) == []

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest -q

.. [100%]

2 passed in 0.02 seconds

[备注]

我们可以像这样指定多个fixture：

@pytest.mark.usefixtures("cleandir", "anotherfixture")

'''

例子模块级别的fixture

'''

[conftest.py]

import pytest

import tempfile

import os

@pytest.fixture()

def cleandir():

newpath = tempfile.mkdtemp()

os.chdir(newpath)

'''

import pytest

import os

pytestmark = pytest.mark.usefixtures("cleandir")

class TestDirectoryInit(object):

def test_cwd_starts_empty(self):

assert os.listdir(os.getcwd()) == []

with open('myfile','w') as f:

f.write('hello')

class TestDirectoryInit2(object):

def test_cwd_again_starts_empty(self):

assert os.listdir(os.getcwd()) == []

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest -q

.. [100%]

2 passed in 0.02 seconds

'''

[注意]

分配的变量必须被称为pytestmark，例如，分配foomark不会激活fixture。

例子我们可以将项目中所有测试所需的fixture放入一个pytest.ini文件中

'''

我们可以将项目中所有测试所需的fixture放入一个pytest.ini文件中，内容如下：

[pytest]

usefixtures = cleandir

[conftest.py]文件内容如下：

import pytest

import tempfile

import os

@pytest.fixture()

def cleandir():

newpath = tempfile.mkdtemp()

os.chdir(newpath)

同目录下[test_two.py]

import os

class TestDirectoryInit2(object):

def test_cwd_again_starts_empty(self):

assert os.listdir(os.getcwd()) == []

'''

import os

class TestDirectoryInit(object):

def test_cwd_starts_empty(self):

assert os.listdir(os.getcwd()) == []

with open('myfile','w') as f:

f.write('hello')

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest -q

.. [100%]

2 passed in 0.02 seconds

'''

例子自动使用fixture

'''

有时候，我们可能希望自动调用fixture，而不是显式生命函数参数或使用usefixtures装饰器，例如，我们有一个数据库fixture，它有一个开始、回滚、提交的体系结构

我们希望通过一个事务和一个回滚自动地包含每一个测试方法

'''

import pytest

class DB(object):

def init(self):

self.intransaction = []

def begin(self,name):

    self.intransaction.append(name)

def rollback(self):

    self.intransaction.pop()

@pytest.fixture(scope='module')

def db():

return DB()

class TestClass(object):

@pytest.fixture(autouse=True)

def transaction(self,request,db):

db.begin(request.function.name)

yield

db.rollback()

def test_method1(self,db):

    assert db.intransaction == ['test_method1']

def test_method2(self,db):

    assert db.intransaction == ['test_method2']

'''

类级别的transact fixture被标记为autouse=true，

这意味着类中的所有测试方法将使用该fixture，而不需要在测试函数签名或类级别的usefixtures装饰器中陈述它。如果我们运行它，会得到两个通过的测试

C:/Users/rq/PycharmProjects/untitled/test1>pytest -q

.. [100%]

2 passed in 0.02 seconds

'''

'''

以下是在其他范围内如何使用自动fixture：

自动fixture遵循scope=关键字参数，如果一个自动fixture的scope='session'，它将只运行一次，不管它在哪里定义。scope='class'表示每个类会运行一次，等等。

如果在一个测试模块中定义一个自动fixture，所有的测试函数都会自动使用它。

如果在conftest.py文件中定义了自动fixture，那么在其目录下的所有测试模块中的所有测试都将调用fixture。

最后，要小心使用自动fixture，如果我们在插件中定义了一个自动fixture，它将在插件安装的所有项目中的所有测试中被调用。例如，在pytest.ini文件中，这样一个全局性的fixture应该真的应该做任何工作，避免无用的导入或计算。

'''

例子 transaction 方法名字是自定义的，叫什么都行

例子如果在conftest.py文件中定义了自动fixture，那么在其目录下的所有测试模块中的所有测试都将调用fixture

'''

[conftest.py]

import pytest

class DB(object):

def init(self):

self.intransaction = []

def begin(self,name):

    self.intransaction.append(name)

def rollback(self):

    self.intransaction.pop()

@pytest.fixture(scope='module')

def db():

return DB()

[test_two.py]

import pytest

class TestClass(object):

@pytest.fixture(autouse=True)

def transaction(self,request,db):

db.begin(request.function.name)

yield

db.rollback()

def test_method3(self,db):

    assert db.intransaction == ['test_method3']

'''

import pytest

class TestClass(object):

@pytest.fixture(autouse=True)

def transaction(self,request,db):

db.begin(request.function.name)

yield

db.rollback()

def test_method1(self,db):

    assert db.intransaction == ['test_method1']

def test_method2(self,db):

    assert db.intransaction == ['test_method2']

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest -q

.. [100%]

3 passed in 0.02 seconds

'''

例子 transact fixture定义放在conftest.py文件

'''

[conftest.py]

import pytest

class DB(object):

def init(self):

self.intransaction = []

def begin(self,name):

    self.intransaction.append(name)

def rollback(self):

    self.intransaction.pop()

@pytest.fixture(scope='module')

def db():

return DB()

@pytest.fixture

def transact(request,db):

db.begin(request.function.name)

yield

db.rollback()

[test_two.py]

import pytest

class TestClass(object):

def test_method3(self,db):

    assert db.intransaction == ['test_method3']

'''

import pytest

@pytest.mark.usefixtures('transact')

class TestClass(object):

def test_method1(self,db):

assert db.intransaction == ['test_method1']

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest -q

.F [100%]

================================== FAILURES ===================================

___________________________ TestClass.test_method3 ____________________________

self = <test1.test_two.TestClass object at 0x000001DAFFBBF278>

db = <test1.conftest.DB object at 0x000001DAFFBBF208>

def test_method3(self,db):

  assert db.intransaction == ['test_method3']

E AssertionError: assert [] == ['test_method3']

E Right contains more items, first extra item: 'test_method3'

E Full diff:

E - []

E + ['test_method3']

test_two.py:8: AssertionError

1 failed, 1 passed in 0.05 seconds

'''

例子上面的例子要通过的话在test_two.py 的 class 上方加@pytest.mark.usefixtures('transact')

'''

[conftest.py]

import pytest

class DB(object):

def init(self):

self.intransaction = []

def begin(self,name):

    self.intransaction.append(name)

def rollback(self):

    self.intransaction.pop()

@pytest.fixture(scope='module')

def db():

return DB()

@pytest.fixture

def transact(request,db):

db.begin(request.function.name)

yield

db.rollback()

[test_two.py]

import pytest

@pytest.mark.usefixtures('transact')

class TestClass(object):

def test_method3(self,db):

    assert db.intransaction == ['test_method3']

'''

import pytest

@pytest.mark.usefixtures('transact')

class TestClass(object):

def test_method1(self,db):

assert db.intransaction == ['test_method1']

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest -q

.. [100%]

2 passed in 0.02 seconds

'''

例子 pytest.ini 形式

'''

[pytest.ini]内容如下：

[pytest]

usefixtures = transact

[test_two.py]内容如下：

import pytest

class TestClass(object):

def test_method3(self,db):

    assert db.intransaction == ['test_method3']

'''

class TestClass(object):

def test_method1(self,db):

assert db.intransaction == ['test_method1']

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest -q

.. [100%]

2 passed in 0.02 seconds

'''

【覆盖不同级别的fixture】

'''在相对较大的测试套件中，我们很可能需要使用本地定义的套件重写全局或根fixture，从而保持测试代码的可读性和可维护性。'''

例子覆盖文件夹级别的fixture

'''

[test1/conftest.py]

import pytest

@pytest.fixture

def username():

return 'username'

[test1/subfolder/conftest.py]

import pytest

@pytest.fixture

def username(username):

return 'overridden-' + username

[test1/subfolder/test_two.py]

def test_username(username):

assert username == 'overridden-username'

'''

def test_username(username):

assert username == 'username'

'''

C:/Users/rq/PycharmProjects/untitled/test1>pytest -q

.. [100%]

2 passed in 0.02 seconds

'''

"""

例子覆盖测试模块级别的fixture

import pytest

@pytest.fixture

def username(username):

return

coding=utf-8

"""

例子覆盖测试模块级别的fixture 某个测试模块可以覆盖同名的fixture。

'''

同目录[conftest.py]

coding=utf-8

import pytest

@pytest.fixture

def user():

return 'user'

同目录[test_two.py]

coding=utf-8

import pytest

@pytest.fixture

def username(user):

return 'overridden-' + user

def test_username(username):

assert username == 'overridden-user'

'''

import pytest

@pytest.fixture

def username(user):

return 'overridden-else-' + user

def test_username(username):

assert username == 'overridden-else-user'

'''

surendeMacBook-Air:~/PycharmProjects/liaoxuefeng_test1/888 suren$pytest -q

..

2 passed in 0.02 seconds

'''

例子直接用测试参数化覆盖fixture fixture值被测试参数值覆盖，即使测试不直接使用它，fixture的值也可以用这种方式重写。

'''

同目录[conftest.py]

coding=utf-8

import pytest

@pytest.fixture

def username():

return 'username'

@pytest.fixture

def other_username(username):

return 'other-' + username

'''

import pytest

@pytest.mark.parametrize('username',['directly-overridden-username'])

def test_username(username):

assert username == 'directly-overridden-username'

@pytest.mark.parametrize('username',['directly-overridden-username-other'])

def test_username_other(other_username):

assert other_username == 'other-directly-overridden-username-other'

'''

surendeMacBook-Air:~/PycharmProjects/liaoxuefeng_test1/888 suren$pytest -q

..

2 passed in 0.02 seconds

'''

例子使用非参数化参数替代参数化的fixture

'''

一个参数化的fixture被一个非参数化的版本覆盖，一个非参数化的fixture被某个测试模块的参数化版本覆盖，这同样适用于测试文件夹级别。

同目录[conftest.py]

coding=utf-8

import pytest

@pytest.fixture(params=['one','two','three'])

def parametrized_username(request):

return request.param

@pytest.fixture

def non_parametrized_username(request):

return 'username'

同目录[test_two.py]

coding=utf-8

import pytest

def test_parametrized_username(parametrized_username):

assert parametrized_username in ['one','two','three']

def test_non_parametrized_username(non_parametrized_username):

assert non_parametrized_username == 'username'

'''

import pytest

@pytest.fixture

def parametrized_username():

return 'overridden-username'

@pytest.fixture(params=['one','two','three'])

def non_parametrized_username(request):

return request.param

def test_parametrized_username(parametrized_username):

assert parametrized_username == 'overridden-username'

def test_non_parametrized_username(non_parametrized_username):

assert non_parametrized_username in ['one','two','three']

'''

surendeMacBook-Air:~/PycharmProjects/liaoxuefeng_test1/888 suren$pytest -q

..

8 passed in 0.02 seconds

'''

"""

Parametrizing tests¶

pytest allows to easily parametrize test functions. For basic docs, see Parametrizing fixtures and test functions.

In the following we provide some examples using the builtin mechanisms.

Generating parameters combinations, depending on command line

Let’s say we want to execute a test with different computation parameters and the parameter range shall be determined by a command line argument. Let’s first write a simple (do-nothing) computation test:

content of test_compute.py

def test_compute(param1):

assert param1 < 4

Now we add a test configuration like this:

content of conftest.py

def pytest_addoption(parser):

parser.addoption("--all", action="store_true",

help="run all combinations")

def pytest_generate_tests(metafunc):

if 'param1' in metafunc.fixturenames:

if metafunc.config.getoption('all'):

end = 5

else:

end = 2

metafunc.parametrize("param1", range(end))

This means that we only run 2 tests if we do not pass --all:

$ pytest -q test_compute.py

.. [100%]

2 passed in 0.12 seconds

We run only two computations, so we see two dots. let’s run the full monty:

$ pytest -q --all

....F [100%]

================================= FAILURES =================================

_____________________________ test_compute[4] ______________________________

param1 = 4

def test_compute(param1):

  assert param1 < 4

E assert 4 < 4

test_compute.py:3: AssertionError

1 failed, 4 passed in 0.12 seconds

As expected when running the full range of param1 values we’ll get an error on the last one.

Different options for test IDs

pytest will build a string that is the test ID for each set of values in a parametrized test. These IDs can be used with -k to select specific cases to run, and they will also identify the specific case when one is failing. Running pytest with --collect-only will show the generated IDs.

Numbers, strings, booleans and None will have their usual string representation used in the test ID. For other objects, pytest will make a string based on the argument name:

content of test_time.py

import pytest

from datetime import datetime, timedelta

testdata = [

(datetime(2001, 12, 12), datetime(2001, 12, 11), timedelta(1)),

(datetime(2001, 12, 11), datetime(2001, 12, 12), timedelta(-1)),

]

@pytest.mark.parametrize("a,b,expected", testdata)

def test_timedistance_v0(a, b, expected):

diff = a - b

assert diff == expected

@pytest.mark.parametrize("a,b,expected", testdata, ids=["forward", "backward"])

def test_timedistance_v1(a, b, expected):

diff = a - b

assert diff == expected

def idfn(val):

if isinstance(val, (datetime,)):

# note this wouldn't show any hours/minutes/seconds

return val.strftime('%Y%m%d')

@pytest.mark.parametrize("a,b,expected", testdata, ids=idfn)

def test_timedistance_v2(a, b, expected):

diff = a - b

assert diff == expected

@pytest.mark.parametrize("a,b,expected", [

pytest.param(datetime(2001, 12, 12), datetime(2001, 12, 11),

timedelta(1), id='forward'),

pytest.param(datetime(2001, 12, 11), datetime(2001, 12, 12),

timedelta(-1), id='backward'),

])

def test_timedistance_v3(a, b, expected):

diff = a - b

assert diff == expected

In test_timedistance_v0, we let pytest generate the test IDs.

In test_timedistance_v1, we specified ids as a list of strings which were used as the test IDs. These are succinct, but can be a pain to maintain.

In test_timedistance_v2, we specified ids as a function that can generate a string representation to make part of the test ID. So our datetime values use the label generated by idfn, but because we didn’t generate a label for timedelta objects, they are still using the default pytest representation:

$ pytest test_time.py --collect-only

=========================== test session starts ============================

platform linux -- Python 3.x.y, pytest-4.x.y, py-1.x.y, pluggy-0.x.y

rootdir: $REGENDOC_TMPDIR, inifile:

collected 8 items

<Module 'test_time.py'>

<Function 'test_timedistance_v0[a0-b0-expected0]'>

<Function 'test_timedistance_v0[a1-b1-expected1]'>

<Function 'test_timedistance_v1[forward]'>

<Function 'test_timedistance_v1[backward]'>

<Function 'test_timedistance_v2[20011212-20011211-expected0]'>

<Function 'test_timedistance_v2[20011211-20011212-expected1]'>

<Function 'test_timedistance_v3[forward]'>

<Function 'test_timedistance_v3[backward]'>

======================= no tests ran in 0.12 seconds =======================

In test_timedistance_v3, we used pytest.param to specify the test IDs together with the actual data, instead of listing them separately.

A quick port of “testscenarios”

Here is a quick port to run tests configured with test scenarios, an add-on from Robert Collins for the standard unittest framework. We only have to work a bit to construct the correct arguments for pytest’s Metafunc.parametrize():

content of test_scenarios.py

def pytest_generate_tests(metafunc):

idlist = []

argvalues = []

for scenario in metafunc.cls.scenarios:

idlist.append(scenario[0])

items = scenario[1].items()

argnames = [x[0] for x in items]

argvalues.append(([x[1] for x in items]))

metafunc.parametrize(argnames, argvalues, ids=idlist, scope="class")

scenario1 = ('basic', {'attribute': 'value'})

scenario2 = ('advanced', {'attribute': 'value2'})

class TestSampleWithScenarios(object):

scenarios = [scenario1, scenario2]

def test_demo1(self, attribute):

    assert isinstance(attribute, str)

def test_demo2(self, attribute):

    assert isinstance(attribute, str)

this is a fully self-contained example which you can run with:

$ pytest test_scenarios.py

=========================== test session starts ============================

platform linux -- Python 3.x.y, pytest-4.x.y, py-1.x.y, pluggy-0.x.y

rootdir: $REGENDOC_TMPDIR, inifile:

collected 4 items

test_scenarios.py .... [100%]

========================= 4 passed in 0.12 seconds =========================

If you just collect tests you’ll also nicely see ‘advanced’ and ‘basic’ as variants for the test function:

$ pytest --collect-only test_scenarios.py

=========================== test session starts ============================

platform linux -- Python 3.x.y, pytest-4.x.y, py-1.x.y, pluggy-0.x.y

rootdir: $REGENDOC_TMPDIR, inifile:

collected 4 items

<Module 'test_scenarios.py'>

<Class 'TestSampleWithScenarios'>

<Function 'test_demo1[basic]'>

<Function 'test_demo2[basic]'>

<Function 'test_demo1[advanced]'>

<Function 'test_demo2[advanced]'>

======================= no tests ran in 0.12 seconds =======================

Note that we told metafunc.parametrize() that your scenario values should be considered class-scoped. With pytest-2.3 this leads to a resource-based ordering.

Deferring the setup of parametrized resources

The parametrization of test functions happens at collection time. It is a good idea to setup expensive resources like DB connections or subprocess only when the actual test is run. Here is a simple example how you can achieve that, first the actual test requiring a db object:

content of test_backends.py

import pytest

def test_db_initialized(db):

# a dummy test

if db.class.name == "DB2":

pytest.fail("deliberately failing for demo purposes")

We can now add a test configuration that generates two invocations of the test_db_initialized function and also implements a factory that creates a database object for the actual test invocations:

content of conftest.py

import pytest

def pytest_generate_tests(metafunc):

if 'db' in metafunc.fixturenames:

metafunc.parametrize("db", ['d1', 'd2'], indirect=True)

class DB1(object):

"one database object"

class DB2(object):

"alternative database object"

@pytest.fixture

def db(request):

if request.param == "d1":

return DB1()

elif request.param == "d2":

return DB2()

else:

raise ValueError("invalid internal test config")

Let’s first see how it looks like at collection time:

$ pytest test_backends.py --collect-only

=========================== test session starts ============================

platform linux -- Python 3.x.y, pytest-4.x.y, py-1.x.y, pluggy-0.x.y

rootdir: $REGENDOC_TMPDIR, inifile:

collected 2 items

<Module 'test_backends.py'>

<Function 'test_db_initialized[d1]'>

<Function 'test_db_initialized[d2]'>

======================= no tests ran in 0.12 seconds =======================

And then when we run the test:

$ pytest -q test_backends.py

.F [100%]

================================= FAILURES =================================

_________________________ test_db_initialized[d2] __________________________

db = <conftest.DB2 object at 0xdeadbeef>

def test_db_initialized(db):

    # a dummy test

    if db.__class__.__name__ == "DB2":

      pytest.fail("deliberately failing for demo purposes")

E Failed: deliberately failing for demo purposes

test_backends.py:6: Failed

1 failed, 1 passed in 0.12 seconds

The first invocation with db == "DB1" passed while the second with db == "DB2" failed. Our db fixture function has instantiated each of the DB values during the setup phase while the pytest_generate_tests generated two according calls to the test_db_initialized during the collection phase.

coding=utf-8

"""

例子 Apply indirect on particular arguments

'''

Very often parametrization uses more than one argument name.

There is opportunity to apply indirect parameter on particular arguments.

t can be done by passing list or tuple of arguments’ names to indirect.

In the example below there is a function test_indirect which uses two fixtures: x and y.

Here we give to indirect the list, which contains the name of the fixture x.

The indirect parameter will be applied to this argument only,

and the value a will be passed to respective fixture function:

'''

import pytest

from datetime import datetime,timedelta

testdata = [

(datetime(2001,12,12),datetime(2001,12,11),timedelta(1)),

(datetime(2001,12,11),datetime(2001,12,12),timedelta(-1)),

]

testdata3 = [

(3,2,1),

(5,2,3)

]

testdata2 = [

('a','b')

]

@pytest.mark.parametrize('a,b,expected',testdata)

def test_timedistance_v0(a,b,expected):

diff = a - b

assert diff == expected

assert 0

@pytest.mark.parametrize('x,y,expected',testdata3)

def test_testdata3(x,y,expected):

diff = x - y

assert diff == expected

assert 0

@pytest.fixture(scope='function')

def x(request):

return request.param*3

@pytest.fixture(scope='function')

def y(request):

return request.param*2

@pytest.mark.parametrize('x,y',testdata2, indirect=['y'])

def test_indirect(x,y):

assert x == 'a'

assert y == 'bb'

assert 0

test_fixture_one.py FFFFF

=================================== FAILURES ===================================

____________________ test_timedistance_v0[a0-b0-expected0] _____________________

a = datetime.datetime(2001, 12, 12, 0, 0)

b = datetime.datetime(2001, 12, 11, 0, 0), expected = datetime.timedelta(1)

@pytest.mark.parametrize('a,b,expected',testdata)

def test_timedistance_v0(a,b,expected):

    diff = a - b

    assert diff == expected

  assert 0

E assert 0

test_fixture_one.py:36: AssertionError

____________________ test_timedistance_v0[a1-b1-expected1] _____________________

a = datetime.datetime(2001, 12, 11, 0, 0)

b = datetime.datetime(2001, 12, 12, 0, 0), expected = datetime.timedelta(-1)

@pytest.mark.parametrize('a,b,expected',testdata)

def test_timedistance_v0(a,b,expected):

    diff = a - b

    assert diff == expected

  assert 0

E assert 0

test_fixture_one.py:36: AssertionError

____________________________ test_testdata3[3-2-1] _____________________________

x = 3, y = 2, expected = 1

@pytest.mark.parametrize('x,y,expected',testdata3)

def test_testdata3(x,y,expected):

    diff = x - y

    assert diff == expected

  assert 0

E assert 0

test_fixture_one.py:42: AssertionError

____________________________ test_testdata3[5-2-3] _____________________________

x = 5, y = 2, expected = 3

@pytest.mark.parametrize('x,y,expected',testdata3)

def test_testdata3(x,y,expected):

    diff = x - y

    assert diff == expected

  assert 0

E assert 0

test_fixture_one.py:42: AssertionError

______________________________ test_indirect[a-b] ______________________________

x = 'a', y = 'bb'

@pytest.mark.parametrize('x,y',testdata2, indirect=['y'])

def test_indirect(x,y):

    assert x == 'a'

    assert y == 'bb'

  assert 0

E assert 0

test_fixture_one.py:56: AssertionError

=========================== 5 failed in 0.06 seconds ===========================

'''

例子

import pytest

from datetime import datetime,timedelta

testdata = [

(datetime(2001,12,12),datetime(2001,12,11),timedelta(1)),

(datetime(2001,12,11),datetime(2001,12,12),timedelta(-1)),

]

testdata3 = [

(3,2,1),

(5,2,3)

]

testdata2 = [

('a','b')

]

@pytest.mark.parametrize('a,b,expected',testdata)

def test_timedistance_v0(a,b,expected):

diff = a - b

assert diff == expected

assert 0

@pytest.mark.parametrize('x,y,expected',testdata3)

def test_testdata3(x,y,expected):

diff = x - y

assert diff == expected

assert 0

@pytest.fixture(scope='function')

def x(request):

return request.param*3

@pytest.fixture(scope='function')

def y(request):

return request.param*2

@pytest.mark.parametrize('x,y',testdata2, indirect=['x','y'])

def test_indirect(x,y):

assert x == 'aaa'

assert y == 'bb'

assert 0

test_fixture_one.py FFFFF

=================================== FAILURES ===================================

____________________ test_timedistance_v0[a0-b0-expected0] _____________________

a = datetime.datetime(2001, 12, 12, 0, 0)

b = datetime.datetime(2001, 12, 11, 0, 0), expected = datetime.timedelta(1)

@pytest.mark.parametrize('a,b,expected',testdata)

def test_timedistance_v0(a,b,expected):

    diff = a - b

    assert diff == expected

  assert 0

E assert 0

test_fixture_one.py:158: AssertionError

____________________ test_timedistance_v0[a1-b1-expected1] _____________________

a = datetime.datetime(2001, 12, 11, 0, 0)

b = datetime.datetime(2001, 12, 12, 0, 0), expected = datetime.timedelta(-1)

@pytest.mark.parametrize('a,b,expected',testdata)

def test_timedistance_v0(a,b,expected):

    diff = a - b

    assert diff == expected

  assert 0

E assert 0

test_fixture_one.py:158: AssertionError

____________________________ test_testdata3[3-2-1] _____________________________

x = 3, y = 2, expected = 1

@pytest.mark.parametrize('x,y,expected',testdata3)

def test_testdata3(x,y,expected):

    diff = x - y

    assert diff == expected

  assert 0

E assert 0

test_fixture_one.py:164: AssertionError

____________________________ test_testdata3[5-2-3] _____________________________

x = 5, y = 2, expected = 3

@pytest.mark.parametrize('x,y,expected',testdata3)

def test_testdata3(x,y,expected):

    diff = x - y

    assert diff == expected

  assert 0

E assert 0

test_fixture_one.py:164: AssertionError

______________________________ test_indirect[a-b] ______________________________

x = 'aaa', y = 'bb'

@pytest.mark.parametrize('x,y',testdata2, indirect=['x','y'])

def test_indirect(x,y):

    assert x == 'aaa'

    assert y == 'bb'

  assert 0

E assert 0

test_fixture_one.py:178: AssertionError

=========================== 5 failed in 0.07 seconds ===========================

[备注]

这个函数的ID如果没有显式提供，则根据参数拼接，如果根据参数值拼接后的字符串不长，则按照参数值拼接结果

如果反之，则按照参数名拼接结果

'''

例子 Parametrizing test methods through per-class configuration

a = [dict(c=1,b=2,z=0),dict(a=3,b=3),]

b = [dict(a=1,b=0),]

aa = sorted(a[0])

bb = sorted(b[0])

print (a[0]) #{'c': 1, 'b': 2, 'z': 0}

print (aa) #['b', 'c', 'z']

print (b[0]) #{'a': 1, 'b': 0}

print (bb) #['a', 'b']

print (a[0][aa[0]]) #2

funcarglist = [dict(a=1, b=2), dict(a=3, b=3), ]

argnames = sorted(funcarglist[0])

print (argnames) #['a', 'b']

argvalues = [funcargs[name] for name in argnames for funcargs in funcarglist]

argvalues2 = [[funcargs[name] for name in argnames]for funcargs in funcarglist]

argvalues4 = [[funcargs[name] for funcargs in funcarglist] for name in argnames]

argvalues3 = [[funcargs[name] for name in argnames for funcargs in funcarglist]]

print (argvalues) #[1, 3, 2, 3]

print (argvalues2) #[[1, 2], [3, 3]]

print (argvalues3) #[[1, 3, 2, 3]]

print (argvalues4) #[[1, 3], [2, 3]]

import pytest

def pytest_generate_tests(metafunc):

# called once per each test function

funcarglist = metafunc.cls.params[metafunc.function.name]

argnames = sorted(funcarglist[0])

metafunc.parametrize(argnames, [[funcargs[name] for name in argnames]

for funcargs in funcarglist])

class TestClass(object):

# a map specifying multiple argument sets for a test method

params = {

'test_equals': [dict(a=1, b=2), dict(a=3, b=3), ],

'test_zerodivision': [dict(a=1, b=0), ],

}

def test_equals(self, a, b):

    assert a == b

def test_zerodivision(self, a, b):

    pytest.raises(ZeroDivisionError, "a/b")

'''

surendeMacBook-Air:~/PycharmProjects/liaoxuefeng_test1/888 suren$pytest -q

F..

=================================== FAILURES ===================================

__________________________ TestClass.test_equals[1-2] __________________________

self = <test_fixture_one.TestClass object at 0x10ec61fd0>, a = 1, b = 2

def test_equals(self, a, b):

  assert a == b

E assert 1 == 2

test_fixture_one.py:306: AssertionError

1 failed, 2 passed in 0.06 seconds

'''

"""

例子 Indirect parametrization of optional implementations/imports

'''

content of conftest.py

import pytest

@pytest.fixture(scope="session")

def basemod(request):

return pytest.importorskip("base")

@pytest.fixture(scope="session", params=["opt1", "opt2"])

def optmod(request):

return pytest.importorskip(request.param)

And then a base implementation of a simple function:

content of base.py

def func1():

return 1

And an optimized version:

content of opt1.py

def func1():

return 1.0001

And finally a little test module:

content of test_module.py

def test_func1(basemod, optmod):

assert round(basemod.func1(), 3) == round(optmod.func1(), 3)

If you run this with reporting for skips enabled:

$ pytest -rs test_module.py

=========================== test session starts ============================

platform linux -- Python 3.x.y, pytest-4.x.y, py-1.x.y, pluggy-0.x.y

rootdir: $REGENDOC_TMPDIR, inifile:

collected 2 items

test_module.py .s [100%]

========================= short test summary info ==========================

SKIP [1] $REGENDOC_TMPDIR/conftest.py:11: could not import 'opt2'

=================== 1 passed, 1 skipped in 0.12 seconds ====================

'''

例子 Set marks or test ID for individual parametrized test

'''

Set marks or test ID for individual parametrized test

Use pytest.param to apply marks or set test ID to individual parametrized test. For example:

content of test_pytest_param_example.py

import pytest

@pytest.mark.parametrize('test_input,expected', [

('3+5', 8),

pytest.param('1+7', 8,

marks=pytest.mark.basic),

pytest.param('2+4', 6,

marks=pytest.mark.basic,

id='basic_2+4'),

pytest.param('69', 42,

marks=[pytest.mark.basic, pytest.mark.xfail],

id='basic_69'),

])

def test_eval(test_input, expected):

assert eval(test_input) == expected

In this example, we have 4 parametrized tests. Except for the first test, we mark the rest three parametrized tests with the custom marker basic, and for the fourth test we also use the built-in mark xfail to indicate this test is expected to fail. For explicitness, we set test ids for some tests.

Then run pytest with verbose mode and with only the basic marker:

$ pytest -v -m basic

=========================== test session starts ============================

platform linux -- Python 3.x.y, pytest-4.x.y, py-1.x.y, pluggy-0.x.y -- $PYTHON_PREFIX/bin/python3.6

cachedir: .pytest_cache

rootdir: $REGENDOC_TMPDIR, inifile:

collecting ... collected 17 items / 14 deselected

test_pytest_param_example.py::test_eval[1+7-8] PASSED [ 33%]

test_pytest_param_example.py::test_eval[basic_2+4] PASSED [ 66%]

test_pytest_param_example.py::test_eval[basic_6*9] xfail [100%]

============ 2 passed, 14 deselected, 1 xfailed in 0.12 seconds ============

As the result:

Four tests were collected

One test was deselected because it doesn’t have the basic mark.

Three tests with the basic mark was selected.

The test test_eval[1+7-8] passed, but the name is autogenerated and confusing.

The test test_eval[basic_2+4] passed.

The test test_eval[basic_6*9] was expected to fail and did fail.

'''

【备注】上面的例子我自己运行提示"AttributeError: 'module' object has no attribute 'param'" 原因不明

"""

例子换一种运行方式

'''

[conftest.py]

encoding=utf-8

import pytest

def pytest_addoption(parser):

parser.addoption(

'--cmdopt',action='store',default='type1',help='my option: type1 or type2'

)

@pytest.fixture

def cmdopt(request):

return request.config.getoption('--cmdopt')

'''

import pytest

def test_answer(cmdopt):

if cmdopt == 'type1':

print ('first')

elif cmdopt == 'type2':

print ('second')

assert 0

if name == "main":

#方法一

#pytest.main(['-s','test_fixture_one.py','--cmdopt=type2'])

#方法二

pytest.main(['-s','test_fixture_one.py','--cmdopt','type2'])

'''

C:/Users/rq/AppData/Local/Programs/Python/Python37/python.exe C:/Users/rq/PycharmProjects/untitled/test_fixture_one.py

============================= test session starts =============================

platform win32 -- Python 3.7.0, pytest-3.4.0, py-1.7.0, pluggy-0.6.0

rootdir: C:/Users/rq/PycharmProjects/untitled, inifile:

plugins: xdist-1.22.0, rerunfailures-4.1, metadata-1.7.0, html-1.16.1, forked-0.2

collected 1 item

test_fixture_one.py second

F

================================== FAILURES ===================================

_________________________________ test_answer _________________________________

cmdopt = 'type2'

def test_answer(cmdopt):

    if cmdopt == 'type1':

        print ('first')

    elif cmdopt == 'type2':

        print ('second')

  assert 0

E assert 0

test_fixture_one.py:13: AssertionError

========================== 1 failed in 0.04 seconds ===========================

'''

例子 pytest的参数化通过命令行

'''

[conftest.py]

encoding=utf-8

import pytest

def pytest_addoption(parser):

parser.addoption('--al',action='store_true',help='run all combinations')

def pytest_generate_tests(metafunc):

if 'param2' in metafunc.fixturenames:

if metafunc.config.option.al:

end = 103

else:

end = 2

metafunc.parametrize('param2',range(101,end))

'''

def test_compute(param2):

assert param2 == 100

'''

C:/Users/rq/PycharmProjects/untitled>pytest -q test_fixture_one.py --al

FF [100%]

================================== FAILURES ===================================

______________________________ test_compute[101] ______________________________

param2 = 101

def test_compute(param2):

  assert param2 == 100

E assert 101 == 100

test_fixture_one.py:70: AssertionError

______________________________ test_compute[102] ______________________________

param2 = 102

def test_compute(param2):

  assert param2 == 100

E assert 102 == 100

test_fixture_one.py:70: AssertionError

2 failed in 0.04 seconds

执行py.test -q test_compute.py 会发现只有2个case

'''

例子 Different options for test IDs

import pytest

from datetime import datetime,timedelta

testdata = [

(datetime(2001,12,12),datetime(2001,12,11),timedelta(1)),

(datetime(2001,12,11),datetime(2001,12,12),timedelta(-1)),

]

@pytest.mark.parametrize('a,b,expected',testdata)

def test_timedistance_v0(a,b,expected):

diff = a - b

assert diff == expected

@pytest.mark.parametrize('a,b,expected',testdata,ids=['forward','backward'])

def test_timedistance_v1(a,b,expected):

diff = a - b

assert diff == expected

def idfn(val):

if isinstance(val,(datetime,)):

return val.strftime('%Y%m%d')

@pytest.mark.parametrize('a,b,expected',testdata,ids=idfn)

def test_timedistance_v2(a,b,expected):

diff = a - b

assert diff == expected

@pytest.mark.parametrize('a,b,expected',[

pytest.param(datetime(2001,12,12),datetime(2001,12,11),timedelta(1),id='forward'),

pytest.param(datetime(2001,12,11),datetime(2001,12,12),timedelta(-1),id='backward'),

])

def test_timedistance_v3(a,b,expected):

diff = a - b

assert diff == expected

'''

C:/Users/rq/PycharmProjects/untitled>pytest --collect-only

============================= test session starts =============================

platform win32 -- Python 3.7.0, pytest-3.4.0, py-1.7.0, pluggy-0.6.0

rootdir: C:/Users/rq/PycharmProjects/untitled, inifile:

plugins: xdist-1.22.0, rerunfailures-4.1, metadata-1.7.0, html-1.16.1, forked-0.2

collected 8 items

<Module 'test_fixture_one.py'>

<Function 'test_timedistance_v0[a0-b0-expected0]'>

<Function 'test_timedistance_v0[a1-b1-expected1]'>

<Function 'test_timedistance_v1[forward]'>

<Function 'test_timedistance_v1[backward]'>

<Function 'test_timedistance_v2[20011212-20011211-expected0]'>

<Function 'test_timedistance_v2[20011211-20011212-expected1]'>

<Function 'test_timedistance_v3[forward]'>

<Function 'test_timedistance_v3[backward]'>

======================== no tests ran in 0.03 seconds =========================

'''

test_fixture_one.py ........ [100%]

========================== 8 passed in 0.03 seconds ===========================

'''

例子 A quick port of “testscenarios”

def pytest_generate_tests(metafunc):

idlist = []

argvalues = []

for scenario in metafunc.cls.scenarios:

idlist.append(scenario[0])

items = scenario[1].items()

argnames = [x[0] for x in items]

argvalues.append([x[1] for x in items])

metafunc.parametrize(argnames,argvalues,ids=idlist,scope='class')

scenario1 = ('basic', {'attribute': 'value'})

scenario2 = ('advanced', {'attribute1': 'value2'})

class TestSampleWithScenarios(object):

scenarios = [scenario1,scenario2]

def test_demo1(self,attribute):

    assert isinstance(attribute,str)

    assert 0

def test_demo2(self,attribute):

    assert isinstance(attribute,str)

    assert 0

=================================== ERRORS ====================================

____________________ ERROR collecting test_fixture_one.py _____________________

test_fixture_one.py:206: in pytest_generate_tests

metafunc.parametrize(argnames,argvalues,ids=idlist,scope='class')

../../appdata/local/programs/python/python37/lib/site-packages/_pytest/python.py:805: in parametrize

self.function, name, arg))

E ValueError: <function TestSampleWithScenarios.test_demo1 at 0x0000027853D39950> uses no argument 'attribute1'

!!!!!!!!!!!!!!!!!!! Interrupted: 1 errors during collection !!!!!!!!!!!!!!!!!!!

=========================== 1 error in 0.10 seconds ===========================

'''

例子把scenario2中改成attribute，就

test_fixture_one.py FFFF [100%]

================================== FAILURES ===================================

__________________ TestSampleWithScenarios.test_demo1[basic] __________________

self = <test_fixture_one.TestSampleWithScenarios object at 0x000001945291EFD0>

attribute = 'value'

def test_demo1(self,attribute):

    assert isinstance(attribute,str)

  assert 0

E assert 0

test_fixture_one.py:218: AssertionError

__________________ TestSampleWithScenarios.test_demo2[basic] __________________

self = <test_fixture_one.TestSampleWithScenarios object at 0x00000194528F19E8>

attribute = 'value'

def test_demo2(self,attribute):

    assert isinstance(attribute,str)

  assert 0

E assert 0

test_fixture_one.py:222: AssertionError

________________ TestSampleWithScenarios.test_demo1[advanced] _________________

self = <test_fixture_one.TestSampleWithScenarios object at 0x0000019452911DA0>

attribute = 'value2'

def test_demo1(self,attribute):

    assert isinstance(attribute,str)

  assert 0

E assert 0

test_fixture_one.py:218: AssertionError

________________ TestSampleWithScenarios.test_demo2[advanced] _________________

self = <test_fixture_one.TestSampleWithScenarios object at 0x00000194528F1DD8>

attribute = 'value2'

def test_demo2(self,attribute):

    assert isinstance(attribute,str)

  assert 0

E assert 0

test_fixture_one.py:222: AssertionError

========================== 4 failed in 0.06 seconds ===========================

'''

"""

Deferring the setup of parametrized resources

import pytest

def test_db_initialized(db):

if db.class.name == 'DB2':

pytest.fail('deliberately failing for demo purposes')

encoding=utf-8

"""

'''

[conftest.py]

import pytest

def pytest_addoption(parser):

parser.addoption(

'--runslow',action='store_true',default=False,help='run slow tests'

)

def pytest_collection_modifyitems(config,items):

if config.getoption('--runslow'):

return

skip_slow = pytest.mark.skip(reason='need --runslow option to run')

for item in items:

if item in items:

if 'slowo' in item.keywords:

item.add_marker(skip_slow)

'''

import pytest

def test_func_fast():

pass

@pytest.mark.slowo

def test_func_sllow():

pass

'''

C:/Users/rq/PycharmProjects/untitled>pytest -rs

============================= test session starts =============================

platform win32 -- Python 3.7.0, pytest-3.4.0, py-1.7.0, pluggy-0.6.0

rootdir: C:/Users/rq/PycharmProjects/untitled, inifile:

plugins: xdist-1.22.0, rerunfailures-4.1, metadata-1.7.0, html-1.16.1, forked-0.2

collected 2 items

test_fixture_one.py .s [100%]

=========================== short test summary info ===========================

SKIP [1] test_fixture_one.py:9: need --runslow option to run

===================== 1 passed, 1 skipped in 0.02 seconds =====================

'''

例子 Control skipping of tests according to command line option

'''

[conftest.py]

import pytest

def pytest_addoption(parser):

parser.addoption(

'--runslow',action='store_true',default=False,help='run slow tests'

)

'''

import pytest

def test_func_fast():

pass

@pytest.mark.slowo

def test_func_sllow():

pas

'''

C:/Users/rq/PsycharmProjects/untitled>pytest --runslow

============================= test session starts =============================

platform win32 -- Python 3.7.0, pytest-3.4.0, py-1.7.0, pluggy-0.6.0

rootdir: C:/Users/rq/PycharmProjects/untitled, inifile:

plugins: xdist-1.22.0, rerunfailures-4.1, metadata-1.7.0, html-1.16.1, forked-0.2

collected 2 items

test_fixture_one.py .. [100%]

========================== 2 passed in 0.02 seconds ===========================

'''

例子

import pytest

def checkconfig(x):

tracebackhide = True

if not hasattr(x,'config'):

pytest.fail('not configured:%s' % (x,))

def test_something():

checkconfig(42)

'''

C:/Users/rq/PycharmProjects/untitled>pytest -q test_fixture_one.py

F [100%]

================================== FAILURES ===================================

_______________________________ test_something ________________________________

def test_something():

  checkconfig(42)

E Failed: not configured:42

test_fixture_one.py:102: Failed

1 failed in 0.03 seconds

'''

'''

If you only want to hide certain exceptions, you can set tracebackhide to a callable which gets the ExceptionInfo object.

You can for example use this to make sure unexpected exception types aren’t hidden:

'''

例子

import operator

import pytest

class ConfigException(Exception):

pass

def checkconfig(x):

tracebackhide = operator.methodcaller("errisinstance", ConfigException)

if not hasattr(x, "config"):

raise ConfigException("not configured: %s" % (x,))

def test_something():

  checkconfig(42)

E test_fixture_one.ConfigException: not configured: 42

test_fixture_one.py:135: ConfigException

1 failed in 0.03 seconds

'''

例子 Detect if running from within a pytest run

'''

[conftest.py]

encoding=utf-8

def pytest_configure(config):

import sys

sys._called_from_test = True

def pytest_unconfigure(config):

import sys

del sys._called_from_test

'''

'''

Usually it is a bad idea to make application code behave differently if called from a test.

But if you absolutely must find out if your application code is running from a test you can do something like this

'''

import sys

def test_sysconfig():

if hasattr(sys,'_called_from_test'):

print ('has_called_from_test')

else:

print ('has not _called_from_test')

assert 0

'''

C:/Users/rq/PycharmProjects/untitled>pytest -q test_fixture_one.py

F [100%]

================================== FAILURES ===================================

_______________________________ test_sysconfig ________________________________

def test_sysconfig():

    if hasattr(sys,'_called_from_test'):

        print ('has_called_from_test')

    else:

        print ('has not _called_from_test')

  assert 0

E assert 0

test_fixture_one.py:167: AssertionError

---------------------------- Captured stdout call -----------------------------

has_called_from_test

1 failed in 0.03 seconds

'''

例子 Adding info to test report header 正例

'''

[conftest]

encoding=utf-8

def pytest_report_header(config):

return 'project deps:mylib-1.1'

'''

'''

C:/Users/rq/PycharmProjects/untitled>pytest

============================= test session starts =============================

platform win32 -- Python 3.7.0, pytest-3.4.0, py-1.7.0, pluggy-0.6.0

project deps:mylib-1.1

rootdir: C:/Users/rq/PycharmProjects/untitled, inifile:

plugins: xdist-1.22.0, rerunfailures-4.1, metadata-1.7.0, html-1.16.1, forked-0.2

collected 0 items

======================== no tests ran in 0.02 seconds =========================

'''

例子 Adding info to test report header 反例 conftest.py 没有 def pytest_report_header(config):

'''

$ pytest

=========================== test session starts ============================

platform linux -- Python 3.x.y, pytest-4.x.y, py-1.x.y, pluggy-0.x.y

rootdir: $REGENDOC_TMPDIR, inifile:

collected 0 items

======================= no tests ran in 0.12 seconds =======================

'''

例子 You may consider config.getoption('verbose') in order to display more information if applicable

'''

[conftest.py]

encoding=utf-8

def pytest_report_header(config):

if config.getoption('verbose')>0:

return ['info1:did you know that...','did you?']

'''

'''

C:/Users/rq/PycharmProjects/untitled>pytest -v

============================= test session starts =============================

platform win32 -- Python 3.7.0, pytest-3.4.0, py-1.7.0, pluggy-0.6.0 -- c:/users/rq/appdata/local/programs/python/python37/python.exe

cachedir: .pytest_cache

metadata: {'Python': '3.7.0', 'Platform': 'Windows-10-10.0.17134-SP0', 'Packages': {'pytest': '3.4.0', 'py': '1.7.0', 'pluggy': '0.6.0'}, 'Plugins': {'xdist': '1.22.0', 'rerunfailures': '4.1', 'metadata': '1.7.0', 'html': '1.16.1

', 'forked': '0.2'}, 'JAVA_HOME': 'C://Program Files//Java//jdk1.8.0_181'}

info1:did you know that...

did you?

rootdir: C:/Users/rq/PycharmProjects/untitled, inifile:

plugins: xdist-1.22.0, rerunfailures-4.1, metadata-1.7.0, html-1.16.1, forked-0.2

collected 0 items

======================== no tests ran in 0.02 seconds =========================

'''

例子 and nothing when run plainly:

'''

[conftest.py]

encoding=utf-8

def pytest_report_header(config):

if config.getoption('verbose')>0:

return ['info1:did you know that...','did you?']

'''

$ pytest

=========================== test session starts ============================

platform linux -- Python 3.x.y, pytest-4.x.y, py-1.x.y, pluggy-0.x.y

rootdir: $REGENDOC_TMPDIR, inifile:

collected 0 items

======================= no tests ran in 0.12 seconds =======================

'''

例子 profiling test duration

import time

def test_funcfast():

time.sleep(0.1)

def test_funcslow1():

time.sleep(0.2)

def test_funcslow2():

time.sleep(0.3)

'''

C:/Users/rq/PycharmProjects/untitled>pytest --duration=3

============================= test session starts =============================

platform win32 -- Python 3.7.0, pytest-3.4.0, py-1.7.0, pluggy-0.6.0

rootdir: C:/Users/rq/PycharmProjects/untitled, inifile:

plugins: xdist-1.22.0, rerunfailures-4.1, metadata-1.7.0, html-1.16.1, forked-0.2

collected 3 items

test_fixture_one.py ... [100%]

========================== slowest 3 test durations ===========================

0.30s call test_fixture_one.py::test_funcslow2

0.20s call test_fixture_one.py::test_funcslow1

0.10s call test_fixture_one.py::test_funcfast

========================== 3 passed in 0.63 seconds ===========================

'''

例子 incremental testing - test steps

'''

Sometimes you may have a testing situation which consists of a series of test steps.

If one step fails it makes no sense to execute further steps as they are all expected to fail anyway and their tracebacks add no insight.

Here is a simple conftest.py file which introduces an incremental marker which is to be used on classes'''

import pytest

@pytest.mark.incremental

class TestUserHandling(object):

def test_login(self):

pass

def test_modification(self):

assert 0

def test_deletion(self):

    pass

def test_normal():

pass

'''

C:/Users/rq/PycharmProjects/untitled>pytest -rx

============================= test session starts =============================

platform win32 -- Python 3.7.0, pytest-3.4.0, py-1.7.0, pluggy-0.6.0

rootdir: C:/Users/rq/PycharmProjects/untitled, inifile:

plugins: xdist-1.22.0, rerunfailures-4.1, metadata-1.7.0, html-1.16.1, forked-0.2

collected 4 items

test_fixture_one.py .F.. [100%]

================================== FAILURES ===================================

_____________________ TestUserHandling.test_modification ______________________

'''

例子 incremental testing - test steps

'''

[conftest.py]

encoding=utf-8

import pytest

def pytest_runtest_makereport(item,call):

if 'incremental' in item.keywords:

if call.excinfo is not None:

parent = item.parent

parent._previousfailed = item

def pytest_runtest_setup(item):

if 'incremental' in item.keywords:

previousfailed = getattr(item.parent,'_previousfailed',None)

if previousfailed is not None:

pytest.xfail('previous test failed (%s)' % previousfailed.name)

'''

test_fixture_one.py .Fx. [100%]

=========================== short test summary info ===========================

XFAIL test_fixture_one.py::TestUserHandling:

【Python】【自动化测试】【pytest】

[visit exception's basic info]

custom the exc's message

[Making use of context-sensitive comparisons]

[Defining your own assertion comparison]

pytest_assertrepr_compare(config, op, left, right)

coding=utf-8

we have file as 'users.dev.json' in the same directory

[Fixtures as Function arguments]

例子 conftest.py 和当前文件在同一目录下

例子 conftest.py 和当前文件不在同一目录下

例子 conftest.py 不叫 这个名字，换个 conftest1.py

例子 test_fixture_one.py在外部，conftest.py在与test_fixture_one.py同目录的文件夹内部

【Scope: sharing a fixture instance across tests in a class, module or session】

例子

例子 如果拼错一个函数参数或想使用一个不可用的函数参数，将会看到一个包含可用函数参数列表的错误。我们可以使用以下命令看到可用的fixture：

pytest --fixtures test_simplefactory.py

例子 @pytest.fixture(scope='module')

例子

例子 scope='session'运行结果同上

例子 fixture的完成与拆卸代码

例子 没有test_two.py fixture完成与拆卸代码

例子 scope='function'

例子 我们可通过with语句无缝使用yield语法，这样测试完成后，smtp连接被关闭，因为当with语句结束时，smtp对象会自动关闭

例子 如果在设置代码，即yield关键字之前，期间发生异常，则不会调用拆卸代码，即即yield关键字之后的代码

例子 执行拆卸代码的另一种方式是 利用请求上下文对象的addfinalizer方法来注册完成函数。

在上面的代码中，如果“C28”发生异常，“C1”和“C3”仍然会被正确关闭。当然，如果在完成函数注册之前发生异常，那么它将不会被执行。

coding=utf-8

例子 fixture反向获取请求的测试环境

coding=utf-8

例子 再让我们快速创建另一个测试模块，在其模块名称空间中实际设置服务器URL，

coding=utf-8

coding=utf-8

例子 参数化fixture

coding=utf-8

例子

coding=utf-8

encoding=utf-8

例子

例子

例子

例子

例子 使用fixture函数的fixture

例子 通过fixture实例自动分组测试

例子 使用类、模块或项目的fixture

例子 模块级别的fixture

例子 我们可以将项目中所有测试所需的fixture放入一个pytest.ini文件中

例子 自动使用fixture

例子 transaction 方法名字是自定义的，叫什么都行

例子 如果在conftest.py文件中定义了自动fixture，那么在其目录下的所有测试模块中的所有测试都将调用fixture

例子 transact fixture定义放在conftest.py文件

例子 上面的例子要通过的话 在test_two.py 的 class 上方加@pytest.mark.usefixtures('transact')

例子 pytest.ini 形式

【覆盖不同级别的fixture】

例子 覆盖文件夹级别的fixture

例子 覆盖测试模块级别的fixture

coding=utf-8

例子 覆盖测试模块级别的fixture 某个测试模块可以覆盖同名的fixture。

coding=utf-8

coding=utf-8

例子 直接用测试参数化覆盖fixture fixture值被测试参数值覆盖，即使测试不直接使用它，fixture的值也可以用这种方式重写。

coding=utf-8

例子 使用非参数化参数替代参数化的fixture

coding=utf-8

coding=utf-8

content of test_compute.py

content of conftest.py

content of test_time.py

content of test_scenarios.py

content of test_backends.py

content of conftest.py

coding=utf-8

例子 Apply indirect on particular arguments

例子

例子 Parametrizing test methods through per-class configuration

例子 Indirect parametrization of optional implementations/imports

content of conftest.py

content of base.py

content of opt1.py

content of test_module.py

例子 conftest.py 不叫这个名字，换个 conftest1.py

例子如果拼错一个函数参数或想使用一个不可用的函数参数，将会看到一个包含可用函数参数列表的错误。我们可以使用以下命令看到可用的fixture：

例子没有test_two.py fixture完成与拆卸代码

例子我们可通过with语句无缝使用yield语法，这样测试完成后，smtp连接被关闭，因为当with语句结束时，smtp对象会自动关闭

例子如果在设置代码，即yield关键字之前，期间发生异常，则不会调用拆卸代码，即即yield关键字之后的代码

例子执行拆卸代码的另一种方式是利用请求上下文对象的addfinalizer方法来注册完成函数。

例子再让我们快速创建另一个测试模块，在其模块名称空间中实际设置服务器URL，

例子参数化fixture

例子使用fixture函数的fixture

例子通过fixture实例自动分组测试

例子使用类、模块或项目的fixture

例子模块级别的fixture

例子我们可以将项目中所有测试所需的fixture放入一个pytest.ini文件中

例子自动使用fixture

例子如果在conftest.py文件中定义了自动fixture，那么在其目录下的所有测试模块中的所有测试都将调用fixture

例子上面的例子要通过的话在test_two.py 的 class 上方加@pytest.mark.usefixtures('transact')

例子覆盖文件夹级别的fixture

例子覆盖测试模块级别的fixture

例子覆盖测试模块级别的fixture 某个测试模块可以覆盖同名的fixture。

例子直接用测试参数化覆盖fixture fixture值被测试参数值覆盖，即使测试不直接使用它，fixture的值也可以用这种方式重写。

例子使用非参数化参数替代参数化的fixture

例子换一种运行方式

例子 pytest的参数化通过命令行

例子把scenario2中改成attribute，就