装饰器
def login(func):
def inner(arg):
print("passed user verification...")
return func(arg)
return inner
# 本段代码功能等效于tv = login(tv),执行了这段代码也不会发生什么,只是改变了tv的原有功能
# 是一种与语法糖的功能
@login
def tv(name):
print("Welcome to TV page")
1、@login
执行login函数（由于@符号的特殊性）,把自己装饰的函数的函数名当作参数，w1(tv)
tv函数重新定义， tv = login(tv),这样一来tv就变成了inner。
2、以后执行tv的时候，就是执行inner函数了
#!/usr/bin/env python
#coding:utf-8
def Before(request,kargs):
print('before')
def After(request,kargs):
print('after')
# 装饰器框架多了一层,为了本身带参数...
def Filter(before_func,after_func):
# print('haha')
def outer(main_func):
# print('yoyo')
def wrapper(request,kargs):
before_result = before_func(request,kargs)
if(before_result != None):
return before_result;
main_result = main_func(request,kargs)
if(main_result != None):
return main_result;
after_result = after_func(request,kargs)
if(after_result != None):
return after_result;
return wrapper
return outer
@Filter(Before, After)
def Index(request,kargs):
print('index')
1、执行Filter函数，返回的是outer
2、于是就变成了@outer，然后按照装饰器的解释进行运行啦
新Index ＝outer(Index), 即Index == wrapper
1、2步归纳起来就是执行了以下代码：
Index = Filter(Before, After)(Index) 3、以后执行Index的时候，就是执行wrapper函数了
两个装饰器一起用：
# -*- coding:utf-8 -*-
import functools
def w1(*args1, **kwargs1):
def outer(func):
@functools.wraps(func)
def wrapper1(*args, **kwargs):
print('w1')
print(args1)
ret = func(*args, **kwargs)
print(kwargs1)
return ret
return wrapper1
return outer
def w2(*args1, **kwargs1):
def outer(func):
@functools.wraps(func)
def wrapper2(*args, **kwargs):
print('w2')
print(args1)
ret = func(*args, **kwargs)
print(kwargs1)
return ret
return wrapper2
return outer
@w1('d1', d1=1)
@w2('d2', d2=2)
def main(*args, **kwargs):
print('main')
return args, kwargs
ret = main('m', m=1)
print(ret)
print('main\'s name is '+main.__name__)输出：
w1
('d1',)
w2
('d2',)
main
{'d2': 2}
{'d1': 1}
(('m',), {'m': 1})
main's name is main
Process finished with exit code 0
@functools.wraps(func)的功能是为了让函数名不是wrapper,做了类似于wrapper.__name__ = func.__name__这样的动作。
# -*- coding:utf-8 -*-
import functools
def wrapper(func):
@functools.wraps(func)
def wrapper():
print('before')
func()
print('after')
return wrapper
@wrapper
def foo():
print('foo')
foo()
print('foo\'s name is '+foo.__name__)
最后给一个比较难得题目：
# 请编写一个decorator，能在函数调用的前后打印出'begin call'和'end call'的日志。 # # 再思考一下能否写出一个@log的decorator，使它既支持： # # @log # def f(): # pass # 又支持： # # @log('execute') # def f(): # pass解答1，比较直观的解答：
import functools
def log(para):
if callable(para):
@functools.wraps(para)
def wrapper(*args, **kw):
print("start call {0}():".format(para.__name__))
f = para(*args, **kw)
print("end call {0}():".format(para.__name__))
return f
return wrapper
else:
def decorator(func):
@functools.wraps(func)
def wrapper(*args, **kw):
print("{0} {1} ():".format(para, func.__name__))
return func(*args, **kw)
return wrapper
return decorator
@log
def now1():
print("2016-2-5")
@log('execute')
def now2():
print("2016-2-5")
now1()
print('')
now2()输出：
start call now1(): 2016-2-5 end call now1(): execute now2 (): 2016-2-5
import functools
# 最最漂亮的代码!!每一行都很漂亮
def log(arg):
def decorator(func=arg):
text='call' if func==arg else arg
@functools.wraps(func)
def wrapper(*args,**kw):
print('%s %s():' % (text,func.__name__))
return (func(*args, **kw),print('end %s %s():' % (text, func.__name__)))[0]
return wrapper
return decorator() if callable(arg) else decorator
@log('execute')
def now():
print("2016-2-9")
@log
def hello():
print('hello world!')
now()
print(now.__name__)
print()
hello()
print(hello.__name__)
输出：
execute now(): 2016-2-9 end execute now(): now call hello(): hello world! end call hello(): hello
正则表达式
一个讲的不错的博客： http://www.cnblogs.com/PythonHome/archive/2011/11/19/2255459.html直接贴代码：
# -*- coding:utf-8 -*-
import re
pattern = r"\\section"
string = '\sectionxu'
m = re.match(pattern, string, re.IGNORECASE)
print(m)
print(m.group())
pattern = '[0-9]+'
m = re.match(pattern, 'u8us78jkjk') # match只能从头开始匹配
if m:
print(m.group())
pattern = '[0-9]{0,10}'
m = re.findall(pattern, 'u8us78jkjk')
print(m)
pattern = '[a-zA-Z]{1,10}'
m = re.findall(pattern, 'u8us78jkjk')
print(m)
pattern = '\w+'
m = re.findall(pattern, 'u8us7@#8jkjk')
print(m)
pattern = '\w+'
m = re.findall(pattern, 'u8us7@#8jkjk')
print(m)
pattern = '\d+'
m = re.search(pattern, 'u8us7@#8jkjk') # search返回第一个找到的
print(m)
if m:
print(m.group())
pattern = '\d+'
m = re.sub(pattern, '|', 'u8us7@#8jkjk', count=2)
print(m)输出：
<_sre.SRE_Match object; span=(0, 8), match='\\section'> \section ['', '8', '', '', '78', '', '', '', '', ''] ['u', 'us', 'jkjk'] ['u8us7', '8jkjk'] ['u8us7', '8jkjk'] <_sre.SRE_Match object; span=(1, 2), match='8'> 8 u|us|@#8jkjk
再贴一段代码：
# -*- coding:utf-8 -*-
import re
p = re.compile('[a-z]+') # p是一个_sre.SRE_Pattern
print(type(p))
m = p.match("tempo") # m是一个# _sre.SRE_Match object
print(m)
print(m.group())
print(m.start())
print(m.end())
print(m.span())
print(''.center(50, '-'))
s = p.search('::: message') # s是一个# _sre.SRE_Match object
print(s)
print(s.span())
print(s.group())
print(''.center(50, '-'))
p = re.compile('[a-z]+')
m = p.match('string goes here')
if m:
print('Match found: ', m.group())
else:
print('No match')
print(''.center(50, '-'))
p = re.compile(r'\d+')
f = p.findall('12 drummers drumming, 11 pipers piping, 10 lords a-leaping')
print(f)
iterator = p.finditer('12 drummers drumming, 11 ... 10 ...')
print(iterator)
for match in iterator:
print(match) # match是一个_sre.SRE_Match object
print(match.span(), match.group())
m = re.match(r'From\s+', 'From amk Thu May 14 19:12:10 1998')
print(m)
print(m.span(), m.group())
s = re.search('}$', '{block}')
print(s.group())
p = re.compile(r'\bclass\b')
print(p.search('no class at all'))
print(50*'-')
p = re.compile('(ab)*')
m = p.match('ababababab')
print(m)
print(m.group(0,1))
print(m.span(1))
print(50*'-')
p = re.compile('(a(b)c)d')
m = p.match('abcd')
print(m.span(2))
print(m.groups()) # The groups() 方法返回一个包含所有小组字符串的元组，从 1 到 所含的小组号。
p = re.compile(r'(\b\w+)\s+\1')
print(p.search('Paris in the the spring').group())
m = re.match("(?:[abc])+", "abc")
print(m.groups())
print(50*'-')
p = re.compile(r'(?P<word>\b\w+\b)')
m = p.search( '(((( Lots of punctuation )))' )
print(m.group(1))
print(m.group('word'))
print(50*'-')
p = re.compile(r'(?P<word>\b\w+)\s+(?P=word)')
s = p.search('Paris in the the spring')
print(s.group())
print(s.groups())
print(50*'-')
phone_str = "hey my name is alex, and my phone number is 13651054607, please call me if you are pretty!"
phone_str2 = "hey my name is alex, and my phone number is 18651054604, please call me if you are pretty!"
m = re.search("(1)([358]\d{9})",phone_str2)
if m:
print(m.group())
print('计算器'.center(50, '-'))
val = '9-2*-5/3 + 7 /3*99/4*2998 +10 * 568/14'
mch = re.search('\d+\.*\d*[\*\/]+[\+\-]?\d+\.*\d*', val)
print(mch.group())
val = '1-2*((60-30+(-40.0/5)*(9-2*5/3+7/3*99/4*2998+10*568/14))-(-4*3)/(16-3*2))'
content = re.search('\(([\+\-\*\/]*\d+\.*\d*){2,}\)', val).group()
print(content)输出：
<class '_sre.SRE_Pattern'>
<_sre.SRE_Match object; span=(0, 5), match='tempo'>
tempo
0
5
(0, 5)
--------------------------------------------------
<_sre.SRE_Match object; span=(4, 11), match='message'>
(4, 11)
message
--------------------------------------------------
Match found: string
--------------------------------------------------
['12', '11', '10']
<callable_iterator object at 0x10f2081d0>
<_sre.SRE_Match object; span=(0, 2), match='12'>
(0, 2) 12
<_sre.SRE_Match object; span=(22, 24), match='11'>
(22, 24) 11
<_sre.SRE_Match object; span=(29, 31), match='10'>
(29, 31) 10
<_sre.SRE_Match object; span=(0, 5), match='From '>
(0, 5) From
}
<_sre.SRE_Match object; span=(3, 8), match='class'>
--------------------------------------------------
<_sre.SRE_Match object; span=(0, 10), match='ababababab'>
('ababababab', 'ab')
(8, 10)
--------------------------------------------------
(1, 2)
('abc', 'b')
the the
()
--------------------------------------------------
Lots
Lots
--------------------------------------------------
the the
('the',)
--------------------------------------------------
18651054604
-----------------------计算器------------------------
2*-5
(-40.0/5)
旋转二维数组
# -*- coding:utf-8 -*-
array1 = [ i for j in range(3) for i in range(5)]
print(array1)
array2 = [j for j in range(3) for i in range(5)]
print(array2)
print()
matrix = [[row for col in range(5)] for row in range(5)]
for row in matrix:
print(row)
# 矩阵翻转
print('矩阵翻转'.center(50, '-'))
inverse_matrix = [[matrix[col][row] for col in range(len(matrix))] for row in range(len(matrix[1]))]
for row in inverse_matrix:
print(row)
# 下面的方法在一个矩阵原地翻转,只适用于方块阵
print('下面的方法在一个矩阵原地翻转,只适用于方块阵')
array=[[col for col in range(5)] for row in range(5)] #初始化一个4*4数组
for row in array: #旋转前先看看数组长啥样
print(row)
print('-------------')
for i,row in enumerate(array):
for index in range(i,len(row)):
tmp = array[index][i] # get each rows' data by column's index
array[index][i] = array[i][index]
print(tmp, array[i][index]) # = tmp
array[i][index] = tmp
for r in array:
print(r)
print('--one big loop --')输出：
[0, 1, 2, 3, 4, 0, 1, 2, 3, 4, 0, 1, 2, 3, 4] [0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2] [0, 0, 0, 0, 0] [1, 1, 1, 1, 1] [2, 2, 2, 2, 2] [3, 3, 3, 3, 3] [4, 4, 4, 4, 4] -----------------------矩阵翻转----------------------- [0, 1, 2, 3, 4] [0, 1, 2, 3, 4] [0, 1, 2, 3, 4] [0, 1, 2, 3, 4] [0, 1, 2, 3, 4] 下面的方法在一个矩阵原地翻转,只适用于方块阵 [0, 1, 2, 3, 4] [0, 1, 2, 3, 4] [0, 1, 2, 3, 4] [0, 1, 2, 3, 4] [0, 1, 2, 3, 4] ------------- 0 0 0 1 0 2 0 3 0 4 [0, 0, 0, 0, 0] [1, 1, 2, 3, 4] [2, 1, 2, 3, 4] [3, 1, 2, 3, 4] [4, 1, 2, 3, 4] --one big loop -- 1 1 1 2 1 3 1 4 [0, 0, 0, 0, 0] [1, 1, 1, 1, 1] [2, 2, 2, 3, 4] [3, 3, 2, 3, 4] [4, 4, 2, 3, 4] --one big loop -- 2 2 2 3 2 4 [0, 0, 0, 0, 0] [1, 1, 1, 1, 1] [2, 2, 2, 2, 2] [3, 3, 3, 3, 4] [4, 4, 4, 3, 4] --one big loop -- 3 3 3 4 [0, 0, 0, 0, 0] [1, 1, 1, 1, 1] [2, 2, 2, 2, 2] [3, 3, 3, 3, 3] [4, 4, 4, 4, 4] --one big loop -- 4 4 [0, 0, 0, 0, 0] [1, 1, 1, 1, 1] [2, 2, 2, 2, 2] [3, 3, 3, 3, 3] [4, 4, 4, 4, 4] --one big loop --