[python]学习笔记3-字符串内建函数2

>>> a='hello world'

字符串第一个字母大写

>>> a.capitalize()

'Hello world'

 

以（）中指定长度居中显示字符串

>>> a.center(5)

'hello world'

>>> a.center(20)

'   hello world    '

 

统计（）内字符串出现次数

>>> a.count('a')

0

>>> a.count('l')

3

>>> 

 

最大字符

>>> c

'Hello World'

>>> max(c)

'r'

>>> a

'hello world'

>>> max(a)

'w'

 

最小字符

>>> min(a)

' '

 

替换字符

>>> d='is a is b is c is d'

>>> d.replace('is','was')

'was a was b was c was d'

>>> d.replace('is','was',3)

'was a was b was c is d'

>>> d.split()

['is', 'a', 'is', 'b', 'is', 'c', 'is','d']

>>> d.split(' ',3)

['is', 'a', 'is', 'b is c is d']

 

按行切分字符串

>>> e='abc\n123\nppt\n\n5566\n'

>>> e

'abc\n123\nppt\n\n5566\n'

>>> print e

abc

123

ppt

 

5566

 

>>> e.splitlines()

['abc', '123', 'ppt', '', '5566']

>>> e.splitlines(0)

['abc', '123', 'ppt', '', '5566']

>>> e.splitlines(2)

['abc\n', '123\n', 'ppt\n', '\n', '5566\n']

>>> e.splitlines(3)

['abc\n', '123\n', 'ppt\n', '\n', '5566\n']

>>> e.splitlines(6)

['abc\n', '123\n', 'ppt\n', '\n', '5566\n']

>>> e.splitlines(9)

['abc\n', '123\n', 'ppt\n', '\n', '5566\n']

>>> 

 

大小写翻转

>>> c

'Hello World'

>>> c.swapcase()

'hELLO wORLD'

>>> e='123erhgFRFGH'

>>> e.swapcase()

'123ERHGfrfgh'

>>> 

 

标题格式输出

>>> a

'hello world'

>>> a.title()

'Hello World'

>>> 

 

查找（）内字符所在位置，不存在时返回-1

>>> a.find('d')

10

>>> a.index('d')

10

>>> a.find('z')

-1

 

查找（）内字符串所在位置，不存在时抛出异常

>>> a.index('z')

Traceback (most recent call last):

 File "<stdin>", line 1, in <module>

ValueError: substring not found

>>> 

 

istitle判断是否为标题化输出

>>> a='hello world'

>>> a.istitle()

False

>>> b='Hello world'

>>> b.istitle()

False

>>> c='Hello World'

>>> c.istitle()

True

>>> 

 

>>> a

'hello world'

以（）中指定长度左对齐显示字符串

>>> a.ljust(0)

'hello world'

>>> a.ljust(28)

'hello world                '

以（）中指定长度右对齐显示字符串

>>> a.rjust(28)

'                hello world'

 

以（）内字符切分字符串为三部分

>>> a

'hello world'

>>> a.partition('o')

('hell', 'o', ' world')

>>> a.partition(' ')

('hello', ' ', 'world')

>>> a.partition('1')

('hello world', '', '')

>>> a.rpartition('o')

('hello w', 'o', 'rld')

 

以（）内指定长度右对齐输出，左侧以0补充

>>> a.zfill(20)

'000000000hello world'

>>> a.zfill(2)

'hello world'