S.isprintable() -> bool
#如果字符串中的所有字符都是可打印的,或者字符串是空的,则isprintable()方法将返回True。如果不是,则返回False。
#在屏幕上占用打印空间的字符被称为可打印字符。 例如:
字母和符号,数字,标点,空白
>>> ''.isprintable() True >>> '\n'.isprintable() False >>> 's'.isprintable() True >>> '\x1b'.isprintable() False
Return True if all characters in S are considered
printable in repr() or S is empty, False otherwise.
函数名:isspace
S.isspace() -> bool
#如果字符串中只有空格字符,则isspace()方法返回True。如果不是,则返回False。
>>> " ".isspace() True >>> "aa ".isspace() FalseReturn True if all characters in S are whitespace
and there is at least one character in S, False otherwise.
函数名:istitle
S.istitle() -> bool
#如果字符串是一个标题字符串,则istitle()返回True。如果不是,则返回False。
#每个单词首字母大写(Python Is )
>>> 'I Love Python.'.istitle() True >>> 'I Love python.'.istitle() FalseReturn True if S is a titlecased string and there is at least one
character in S, i.e. upper- and titlecase characters may only
follow uncased characters and lowercase characters only cased ones.
Return False otherwise.
函数名:isupper
S.isupper() -> bool
#字符串isupper()方法返回字符串中的所有字符是否大写。
>>> 'I Love python.'.isupper() False >>> 'I LOVE PYTHON.'.isupper() True
函数名:join
S.join(iterable) -> str
#join()方法提供了一种灵活的方式来连接字符串。 它将迭代的每个元素(如列表,字符串和元组)连接到字符串并返回连接的字符串。
>>> s='Python', 'Java', 'Ruby' >>> '->'.join(s) 'Python->Java->Ruby' -------------------- >>> a=['a','b','c'] >>> ''.join(a) 'abc'Return a string which is the concatenation of the strings in the
iterable. The separator between elements is S.
函数名:ljust
S.ljust(width[, fillchar]) -> str
#返回一个给定最小宽度的左对齐字符串。类似centen(),rjust()
>>> a='abc' >>> a.ljust(8,'@') 'abc@@@@@' >>>Return S left-justified in a Unicode string of length width. Padding is
done using the specified fill character (default is a space).
函数名:lower
S.lower() -> str
#将字符串中的所有大写字符转换为小写字符并返回它。
>>> a="ABc" >>> a.lower() 'abc'
Return a copy of the string S converted to lowercase.
函数名:lstrip
S.lstrip([chars]) -> str
#返回一个字符串的副本,该字符串的主要字符被删除(基于字符串参数传递)。
>>> a=" abc" >>> a.lstrip() 'abc' >>> a="http:\\www.baidu.com" >>> a.lstrip('http:\\') 'www.baidu.com'Return a copy of the string S with leading whitespace removed.
If chars is given and not None, remove characters in chars instead.
函数名:maketrans
string.maketrans(x[, y[, z]])
Return a translation table usable for str.translate().
x - If only one argument is supplied, it must be a dictionary.
The dictionary should contain 1-to-1 mapping from a single character string to its translation OR a unicode number (97 for 'a') to its translation.
y - If two arguments are passed, it must be two strings with equal length.
Each character in the first string is a replacement to its corresponding index in the second string.
z - If three arguments are passed, each character in the third argument is mapped to None.
#maketrans()方法是一种静态方法,它创建一个字符到其翻译/替换的一对一映射。
#它为每个字符的翻译创建一个Unicode表示。
#将两字符串(一个字典),形成一一对应映射关系,返回一个字典
>>> dict = {"a": "123", "b": "456", "c": "789"} >>> s='abc' >>> s.maketrans(dict) {97: '123', 98: '456', 99: '789'} >>> s='abc' >>> b='123' >>> str.maketrans(s,b) {97: 49, 98: 50, 99: 51} >>> s=['1','2','3'] >>> a=['b','c','d'] >>> str.maketrans(s,a) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: maketrans() argument 2 must be str, not list
If there are two arguments, they must be strings of equal length, and
in the resulting dictionary, each character in x will be mapped to the
character at the same position in y. If there is a third argument, it
must be a string, whose characters will be mapped to None in the result.
函数名:partition
S.partition(sep) -> (head, sep, tail)
#在参数字符串的第一次出现时分割字符串,并返回包含前分隔符、参数字符串和分离后部分的元组。如果没有找到返回本身,两个空str
>>> string = "Python is fun" >>> string.partition('is') ('Python ', 'is', ' fun') >>> string.partition('a') ('Python is fun', '', '') >>>Search for the separator sep in S, and return the part before it,
the separator itself, and the part after it. If the separator is not
found, return S and two empty strings.