python字符串处理

小灰灰 2022-01-05 10:45 282阅读 0赞

字符串处理绝对是任何一门语言的重点。

### `str.``partition`(*sep*) ###

Split the string at the first occurrence of *sep*, and return a 3-tuple containing the part before the separator, the separator itself, and the part after the separator. If the separator is not found, return a 3-tuple containing the string itself, followed by two empty strings.

mystr = 'hello,!!!world'
    print(mystr.partition(','))
    # output
    ('hello', ',', '!!!world')

### `str.``split`(*sep=None*, *maxsplit=-1*) ###

Return a list of the words in the string, using *sep* as the delimiter string. If *maxsplit* is given, at most *maxsplit* splits are done (thus, the list will have at most `maxsplit+1` elements). If *maxsplit* is not specified or `-1`, then there is no limit on the number of splits (all possible splits are made).

![565026-20170806114738209-1578766456.png][]

### `str.``join`(*iterable*) ###

Return a string which is the concatenation of the strings in *iterable*. A `TypeError` will be raised if there are any non-string values in *iterable*, including `bytes` objects. The separator between elements is the string providing this method.

mylist = ['first', 'second', 'third']
    mystr = '#'.join(mylist)
    print(mystr)
    # output: first#second#third

### `str.``startswith`(*prefix, start, end*) ###

Return `True` if string starts with the *prefix*, otherwise return `False`. *prefix* can also be a tuple of prefixes to look for. With optional *start*, test string beginning at that position. With optional *end*, stop comparing string at that position.

mystr = "this is string example....wow!!!"
    print(mystr.startswith('this'))
    print(mystr.startswith('is', 2, 4))
    print(mystr.startswith('this', 2, 4))

输出如下:

True  
True  
False

### `str.``strip`(\[*chars*\]) ###

Return a copy of the string with the leading and trailing characters removed. The *chars* argument is a string specifying the set of characters to be removed. If omitted or `None`, the *chars* argument defaults to removing whitespace. The *chars*argument is not a prefix or suffix; rather, all combinations of its values are stripped:

![565026-20170816090521896-1845324931.png][]

转载于:https://www.cnblogs.com/gattaca/p/7294357.html

[565026-20170806114738209-1578766456.png]: /images/20211229/2ab9d3bb6c5346868148dca067fdebd8.png
[565026-20170816090521896-1845324931.png]: /images/20211229/1a0445067e5e4a81afd8ea9c638cc81d.png