字符串
python中没有字符的概念==与元组一样，不能直接修改
支持拼接版的修改
>>> str1='asdf'
>>> str1.capitalize()
'Asdf'
>>> str1
'asdf'
>>> str1='DSADas'
>>> str1.casefold()
'dsadas'
>>> str1
'DSADas'
>>> str1.center(40)
' DSADas '
>>> str1
'DSADas'
>>> str1.count('a')
1
>>> str1.count('a',true)
Traceback (most recent call last):
File "<pyshell#9>", line 1, in <module>
str1.count('a',true)
NameError: name 'true' is not defined
>>> str1.endwith(('s')
KeyboardInterrupt
>>> str1.endswith('s')
True
>>> str1='i\tlove\tprogoram'
>>> str1.expandtabs()
'i love progoram'
>>> str1.find('pro')
7
>>> str1.find('f')
-1
>>> str1.index('f')
Traceback (most recent call last):
File "<pyshell#20>", line 1, in <module>
str1.index('f')
ValueError: substring not found
>>> str1.index('pro')
7
isalnum()=isalpha()+isdigit()
>>> str2='周雨佳'
>>> str2.islower() 至少包含一个区分大小写的字符，且这些字符都是小写，返回true
False
istitle()所有单词首字母都是大写，其他字母都是小写
isupper()所有字母都是大写
>>> str2.join('dsds')
'd周雨佳s周雨佳d周雨佳s'
>>> str3=' fdsfsd sfds '
>>> str3.lstrip()
'fdsfsd sfds '
>>> str3.rstrip()
' fdsfsd sfds'
>>> str3.partition('ds')
(' f', 'ds', 'fsd sfds ')
>>> str3.replace('f','z',2)
' zdszsd sfds '
rfind rindex rstrip startswith strip一样的
>>> str3.split('')
Traceback (most recent call last):
File "<pyshell#30>", line 1, in <module>
str3.split('')
ValueError: empty separator
>>> str3.split()
['fdsfsd', 'sfds']
>>> str3
' fdsfsd sfds '
>>> str3.strip('s')
' fdsfsd sfds '
>>> str4='FFSDds'
>>> str4.swap()
Traceback (most recent call last):
File "<pyshell#35>", line 1, in <module>
str4.swap()
AttributeError: 'str' object has no attribute 'swap'
>>> str3.title()
' Fdsfsd Sfds '
>>> str3.translate(str.maketrans('s','z'))
' fdzfzd zfdz '
>>> str3.maketrans('s','z')
{115: 122}
>>> str3.zfill(30)
'00000000000000 fdsfsd sfds '
格式化字符串
>>> str1='asdf'
>>> str1.capitalize()
'Asdf'
>>> str1
'asdf'
>>> str1='DSADas'
>>> str1.casefold()
'dsadas'
>>> str1
'DSADas'
>>> str1.center(40)
' DSADas '
>>> str1
'DSADas'
>>> str1.count('a')
1
>>> str1.count('a',true)
Traceback (most recent call last):
File "<pyshell#9>", line 1, in <module>
str1.count('a',true)
NameError: name 'true' is not defined
>>> str1.endwith(('s')
KeyboardInterrupt
>>> str1.endswith('s')
True
>>> str1='i\tlove\tprogoram'
>>> str1.expandtabs()
'i love progoram'
>>> str1.find('pro')
7
>>> str1.find('f')
-1
>>> str1.index('f')
Traceback (most recent call last):
File "<pyshell#20>", line 1, in <module>
str1.index('f')
ValueError: substring not found
>>> str1.index('pro')
7
>>> str2='周雨佳'
>>> str2.islower()
False
>>> str2.join('dsds')
'd周雨佳s周雨佳d周雨佳s'
>>> str3=' fdsfsd sfds '
>>> str3.lstrip()
'fdsfsd sfds '
>>> str3.rstrip()
' fdsfsd sfds'
>>> str3.partition('ds')
(' f', 'ds', 'fsd sfds ')
>>> str3.replace('f','z',2)
' zdszsd sfds '
>>> str3.split('')
Traceback (most recent call last):
File "<pyshell#30>", line 1, in <module>
str3.split('')
ValueError: empty separator
>>> str3.split()
['fdsfsd', 'sfds']
>>> str3
' fdsfsd sfds '
>>> str3.strip('s')
' fdsfsd sfds '
>>> str4='FFSDds'
>>> str4.swap()
Traceback (most recent call last):
File "<pyshell#35>", line 1, in <module>
str4.swap()
AttributeError: 'str' object has no attribute 'swap'
>>> str3.title()
' Fdsfsd Sfds '
>>> str3.translate(str.maketrans('s','z'))
' fdzfzd zfdz '
>>> str3.maketrans('s','z')
{115: 122}
>>> str3.zfill(30)
'00000000000000 fdsfsd sfds '
>>> "{0} love{1}.{2}".format("i","am",'misszhou')
'i loveam.misszhou'
>>> "{a}{b}{c}".format(a="i",b="am",c="misszhou")
'iammisszhou'
>>> "{a}{b}{0}".format(a="i",b="am","misszhou")
SyntaxError: positional argument follows keyword argument
>>> print('\tz')
z
>>> "{{0}}".format("no")
'{0}'
>>> '{0:.lf}{1}'.format(27.2324,'GB')
Traceback (most recent call last):
File "<pyshell#45>", line 1, in <module>
'{0:.lf}{1}'.format(27.2324,'GB')
ValueError: Format specifier missing precision
>>> '{0:.1f}{1}
SyntaxError: EOL while scanning string literal
>>> '{0:.1f}{1}'.format(27.2324,'GB')
'27.2GB'
%c %s %d o x X f e E g G（根据数字大小选择f e)
>>> '%c' %97
'a'
>>> '%c%c%c' % {97,98,99}
Traceback (most recent call last):
File "<pyshell#49>", line 1, in <module>
'%c%c%c' % {97,98,99}
TypeError: %c requires int or char
>>> '%c%c%c' % (97,98,99)
'abc'
>>> '%s' % 'jkfjdk'
'jkfjdk'
>>> '%d+%d=%d' % (4,5,4+5)
'4+5=9'
>>> '%o' % 12
'14'
>>> '%x' %10
'a'
>>> '%f" %23.43423
SyntaxError: EOL while scanning string literal
>>> '%f'%2343
'2343.000000'
>>> '%e'%342443r5r32
SyntaxError: invalid syntax
>>> '%e'%432434
'4.324340e+05'
格式化操作符辅助指令
>>> '%10d'%5
' 5'
>>> '%-10d'%4
'4 '
>>> '%+d'%4
'+4'
>>> '%+d'%-5
'-5'
>>> '%#o'%432
'0o660'
>>> '%#X'%4543
'0X11BF'
>>> '%#d'%4342
'4342'
>>> '%010d'%4342
'0000004342'
>>> '%-010d'%43543
'43543 '
转义字符也是一样用的
\t \n \r
序列
列表、元组、字符串的共同点
都可以通过索引得到每一个元素
默认索引值是0
可以通过分片的方法得到一个范围内的元素集合
有很多相同的操作符
list
>>> help(list)
Help on class list in module builtins:
class list(object)
| list() -> new empty list
| list(iterable) -> new list initialized from iterable's items
| （迭代：重复反馈过程的活动，目的通常是为了接近和达到所需的目标或结果，每次重复叫做迭代，每次迭代的结果作为下一次的初始值）
| Methods defined here:
|
| __add__(self, value, /)
| Return self+value.
|
| __contains__(self, key, /)
| Return key in self.
|
| __delitem__(self, key, /)
| Delete self[key].
|
| __eq__(self, value, /)
| Return self==value.
|
| __ge__(self, value, /)
| Return self>=value.
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __getitem__(...)
| x.__getitem__(y) <==> x[y]
|
| __gt__(self, value, /)
| Return self>value.
|
| __iadd__(self, value, /)
| Implement self+=value.
|
| __imul__(self, value, /)
| Implement self*=value.
|
| __init__(self, /, *args, **kwargs)
| Initialize self. See help(type(self)) for accurate signature.
|
| __iter__(self, /)
| Implement iter(self).
|
| __le__(self, value, /)
| Return self<=value.
|
| __len__(self, /)
| Return len(self).
|
| __lt__(self, value, /)
| Return self<value.
|
| __mul__(self, value, /)
| Return self*value.n
|
| __ne__(self, value, /)
| Return self!=value.
|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.
|
| __repr__(self, /)
| Return repr(self).
|
| __reversed__(...)
| L.__reversed__() -- return a reverse iterator over the list
|
| __rmul__(self, value, /)
| Return self*value.
|
| __setitem__(self, key, value, /)
| Set self[key] to value.
|
| __sizeof__(...)
| L.__sizeof__() -- size of L in memory, in bytes
|
| append(...)
| L.append(object) -> None -- append object to end
|
| clear(...)
| L.clear() -> None -- remove all items from L
|
| copy(...)
| L.copy() -> list -- a shallow copy of L
|
| count(...)
| L.count(value) -> integer -- return number of occurrences of value
|
| extend(...)
| L.extend(iterable) -> None -- extend list by appending elements from the iterable
|
| index(...)
| L.index(value, [start, [stop]]) -> integer -- return first index of value.
| Raises ValueError if the value is not present.
|
| insert(...)
| L.insert(index, object) -- insert object before index
|
| pop(...)
| L.pop([index]) -> item -- remove and return item at index (default last).
| Raises IndexError if list is empty or index is out of range.
|
| remove(...)
| L.remove(value) -> None -- remove first occurrence of value.
| Raises ValueError if the value is not present.
|
| reverse(...)
| L.reverse() -- reverse *IN PLACE*
|
| sort(...)
| L.sort(key=None, reverse=False) -> None -- stable sort *IN PLACE*
|
| ----------------------------------------------------------------------
| Data and other attributes defined here:
|
| __hash__ = None
>>> a=list()
>>> a
[]
>>> b='i am misszhou'
>>> b=list(b)
>>> b
['i', ' ', 'a', 'm', ' ', 'm', 'i', 's', 's', 'z', 'h', 'o', 'u']
>>> c=(1,1,3,5,8)
>>> c=list(c)
>>> c
[1, 1, 3, 5, 8]
>>> help(tuple)
Help on class tuple in module builtins:
class tuple(object)
| tuple() -> empty tuple
| tuple(iterable) -> tuple initialized from iterable's items
|
| If the argument is a tuple, the return value is the same object.
|
| Methods defined here:
|
| __add__(self, value, /)
| Return self+value.
|
| __contains__(self, key, /)
| Return key in self.
|
| __eq__(self, value, /)
| Return self==value.
|
| __ge__(self, value, /)
| Return self>=value.
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __getitem__(self, key, /)
| Return self[key].
|
| __getnewargs__(...)
|
| __gt__(self, value, /)
| Return self>value.
|
| __hash__(self, /)
| Return hash(self).
|
| __iter__(self, /)
| Implement iter(self).
|
| __le__(self, value, /)
| Return self<=value.
|
| __len__(self, /)
| Return len(self).
|
| __lt__(self, value, /)
| Return self<value.
|
| __mul__(self, value, /)
| Return self*value.n
|
| __ne__(self, value, /)
| Return self!=value.
|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.
|
| __repr__(self, /)
| Return repr(self).
|
| __rmul__(self, value, /)
| Return self*value.
|
| count(...)
| T.count(value) -> integer -- return number of occurrences of value
|
| index(...)
| T.index(value, [start, [stop]]) -> integer -- return first index of value.
| Raises ValueError if the value is not present.
>>> len(a)
0
>>> len(c)
5
>>> c
[1, 1, 3, 5, 8]
>>> max(c)
8
>>> max(b)
'z'
>>> numbers=[1,18,13,0,-23,4,-342]
>>> max(numbers)
18
>>> min(numbers)
-342
>>> chars='1232342'
>>> min(chars)
'1'
>>> tuple1=(1,2,4,5,7,9)
必须是相同类型的才有max min 数字和字符不能比较