描述

expandtabs(卡塔尔(英语:State of Qatar) 方法把字符串中的 tab 符号(‘\t’卡塔尔(英语:State of Qatar)转为空格,tab
符号(‘\t’卡塔尔国默许的空格数是 8。

str字符串常用方法,str字符串

描述

find(卡塔尔 方法检查评定字符串中是不是带有子字符串 str ,假使钦定 beg(开头) 和
end(停止)
范围,则检查是还是不是包罗在钦点范围内,假使钦赐范围内假设含有钦定索引值,重返的是索引值在字符串中的伊始地方。即便不富含索引值,重返-1。

Python字符串str的形式应用,python字符串str

#!usr/bin/env python
# -*-coding:utf-8-*-
#字符串通常用双引号或单引号来表示:'123',"abc","字符串"
#str字符串的常用方法有以下:字符串可以用于赋值临时变量s
#友情提示以下全是python2.x版本演示,python3.x请在print(放入测试打印),例如:print(len(s))
from string import maketrans
s3 = '123'
s2 = '   '
s1 = 'This Is \t Cash'
s='abcdefghijklmnopqrstuvwxyz'
s4 = "0000000this is string example....wow!!!0000000"
s5 = 'ab c\n\nde fg\rkl\r\n'
print s[0:6]    #切片,截取字符串中的一段(以下标的起始位置到结束位置)
print len(s)    #统计字符串的长度
print s.ljust(50,'0'),'--->ljust方法'   #返回一个原字符串右用字符串0填充左对齐并宽度50的新字符串
print s.rjust(50,'0'),'--->rjust方法'   #返回一个原字符串左用字符串0填充右对齐并宽度50的新字符串
print s.capitalize(),'--->capitalize方法'    #返回字符串首字母大写的副本
print s.center(50,'*'),'--->center方法'  #表示原字符串居中两边填充宽度的用法
print format(s, '.3'),'--->format方法'   #格式化输出也可当切片用的方式
print s.upper(),'--->upper方法' #将小写字母转换成大写字母
print s.lower(),'--->lower方法' #将大写字母转换成小写字母
print s3.isdigit(),'--->isdigit方法'   #判断字符串如果是数字返回真True,不是返回假False
print s.startswith('abc'),'--->startswith方法'   #判断字符串是否是以abc开头如果是返回真,否则返回假
print s.endswith('zz'),'--->endswith方法'  #判断字符串是否以yz结尾是返回真,否则返回假
print s1.expandtabs(),'--->expandtabs方法'   #把字符串中的 tab 符号('\t')转为空格,tab 符号('\t')默认的空格数是8
print s.isalnum(),'--->isalnum方法'   #判断字符串至少有一个字符并且所有字符都是字母或数字则返回 True,否则返回 False
print s.isalpha(),'--->isalpha方法'   #判断字符串至少有一个字符并且所有字符都是字母则返回 True,否则返回 False
print s2.isspace(),'--->isspace方法'  #判断字符串中只包含空格,则返回 True,否则返回 False
print s1.istitle(),'--->istitle方法'   #如果字符串中所有的单词拼写首字母是否为大写,且其他字母为小写则返回 True,否则返回 False
print s4.strip("0"),'--->strip方法' #返回移除字符串头尾指定的字符生成的新字符串
print s.find('sd'),'--->find方法'   #检查是否包含在指定范围内,如果包含子字符串返回开始的索引值,否则返回-1。
print s.index('s'),'--->index方法'  #检查是否包含在指定范围内,该方法与find()方法一样,只不过如果不在字符串中会报一个异常
print s.partition("k"),'--->partition方法'  #生成一个分隔符k,第一个为分隔符左边的子串,第二个为分隔符本身,第三个为分隔符右边的子串。
print s1.swapcase(),'--->swapcase方法' #返回大小写字母转换后生成的新字符串
print s5.splitlines(),'--->splitlines方法'   #返回一个包含各行作为元素的列表
print s2.join(s3),'--->join方法'   #返回通过指定字符连接序列中元素后生成的新字符串
print s3.translate(maketrans(s3,s2)) #返回翻译后的字符串(有点复杂)自信百度补脑
print s3.zfill(10),'--->zfill方法'  #返回指定宽度的字符串原字符串右对齐,前面填充0
#以下打印输出:

图片 1

#!usr/bin/env python # -*-coding:utf-8-*-
#字符串平日用双引号或单引号来代表:’123′,”abc”,”字符串”
#str字符串…

描述

Python
casefold(卡塔尔(英语:State of Qatar)方法是Python3.3本子之后引进的,其效劳和 lower() 方法十三分相通,都可以转变字符串中颇负大写字符为小写。

两岸的分别是:lower(卡塔尔(قطر‎方法只对ASCII编码,也正是‘A-Z’有效,对于其余语言(非中文或德语)中把大写转换为小写的处境只好用
casefold(卡塔尔国 方法。

语法

expandtabs(卡塔尔(قطر‎方德文法:

str.expandtabs(tabsize=8)

 

    字符串是编制程序中常用的类型,字符型在内部存款和储蓄器中是以单个方式积攒的,比方name

“alex”,在内部存款和储蓄器中蕴藏的花样为[“a”,”l”,”e”,”x”],由此我们得以应用列表的居多作用来操作字符串,因为本人起始的时候一直在想怎么字符串能够选用切块,能够有目录,起始的时候一直不晓得,后来通晓了Python字符串的仓库储存格局之后才掌握为啥存在此些艺术。上边我们来探视字符串类型中包涵那二个方法:

   
在Python中微微措施上边有注释,那是因为那个艺术运用Python本人编写的,大家精通Python中大多是一直调用C语言中的方法,看不到的那么些是C语言中的方法。

    1.capitalize(self)

    def capitalize(self): # real signature unknown; restored from
__doc__
    ”””
    S.capitalize() -> str
        首字母大写,只是第三个位居第四位第二个首字母大写
    Return a capitalized version of S, i.e. make the first
character
    have upper case and the rest lower case.
    ”””
    return “”

   
capitalize(self卡塔尔(英语:State of Qatar)是位居首位首字母大写,大家知晓还会有三个主意title(卡塔尔(英语:State of Qatar),上面来相比较那多少个方法的不相同点:

    >>> name = “alex is sb”
  >>> name.capitalize()
  ’Alex is sb’
  >>> name.title()
  ’Alex Is Sb’

   
从上边能够见到,capitalize(self卡塔尔(英语:State of Qatar)是位居第二位首字母大写,别的字母超小写;而title(self卡塔尔国方法是具备单词的首字母都大写,那一个在用的时候要通晓是讲求那么字母大写。

    2.casefold(self)

    def casefold(self): # real signature unknown; restored from
__doc__
    ”””
    S.casefold() -> str
        全体首字母小写,等价于lower(卡塔尔(英语:State of Qatar)
    Return a version of S suitable for caseless comparisons.
    ”””
    return “”

    casefold(self卡塔尔(قطر‎是将大写字母转化为小写,等价于lower(self卡塔尔国,实比方下:

    >>> name = “ALEX Is SB”
  >>> name.casefold()
  ’alex is sb’
  >>> name
  ’ALEX Is SB’
  >>> name.lower()
  ’alex is sb’

  3.center(self,width,fillchar=None)

    def center(self, width, fillchar=None): # real signature unknown;
restored from __doc__
    ”””
    S.center(width[, fillchar]) -> str
       
“””center(self,width,fillchar=None卡塔尔是将字符串放到中间,两边加上跋扈符号,暗中认可空格”””
    Return S centered in a string of length width. Padding is
    done using the specified fill character (default is a space)
    ”””
    return “”

   
center(self,width,fillchar=None卡塔尔,美化格式,把self放到中间,钦赐放肆长度的字符,空白处用字符填充,暗许时间和空间字符。示举个例子下:

    >>> name = “您好”
  >>> name.center(12)
  ’     您好     ‘
  >>> name.center(12,”-“)
  ’—–您好—–‘

    4.__format__(self,format_spec)

    def __format__(self, format_spec): # real signature unknown;
restored from __doc__
    ”””
    S.__format__(format_spec) -> str
        字符串的格式化
    Return a formatted version of S as described by format_spec.
    ”””
    return “”

   
__format__(self,format_spec卡塔尔字符串进行格式化,根据大家渴求的格式举行字符串格式化操作。详细可参考()

    >>> tp1 = “My name is {0},and I am {1} years old,I am
{2}”

  >>> tp1.format(“Alex”,”18″,”sb”)

    ‘My name is Alex,and I am 18 years old,I am sb’

    >>> tp2 = “I am {1} years old,my name is {2},and I am
{0}.”

  >>> tp2.format(“sb”,”18″,”Alex”)
  ’I am 18 years old,my name is Alex,and I am sb.’
   
这种格局也可以用在字符串的拼凑上边,使用字符串的format(卡塔尔国方法,在{}大括号中定义索引,告诉Python把哪些值传给索引地方。

    5.__getattribute__(self,*args,**kwargs)

    def __getattribute__(self, *args, **kwargs): # real
signature unknown
    ””” Return getattr(self, name). “””

        “””反射的时候用的”””
    pass

    6.__getitem__(self,*args,**kwargs)

    def __getitem__(self, *args, **kwargs): # real signature
unknown
    ””” Return self[key]. “””

    ”””获得字符串低等个成分,等价于self[key]”””
    pass  

   
正是得到字符串中第几个职位的字符,大家精通字符串在内部存款和储蓄器中是以列表格局积累的,因而能够使用索引来获取单个字符,实比如下:

    >>> name = “Alexissb”
  >>> name.__getitem__(2)
  ’e’
  >>> name[2]
  ’e’
    字符串中索引是从0初叶的,获取字符串中第多少个任务的字符。

    7.__getnewargs__(self,*args,**kwargs)

    def __getnewargs__(self, *args, **kwargs): # real signature
unknown

    ”””__getnewargs__是跟参数有关的”””
    pass

    8.__hash__(self,*args,**kwargs)

    def __hash__(self, *args, **kwargs): # real signature
unknown
    ””” Return hash(self). “””
    pass   

    9.__iter__(self,*args,**kwargs)

    def __iter__(self, *args, **kwargs): # real signature
unknown
    ””” Implement iter(self). “””
    pass

    10.__len__(self,*args,**kwargs)

    def __len__(self, *args, **kwargs): # real signature
unknown
    ””” Return len(self). “””

        “””重回字符串的长度,等价与len(self卡塔尔”””
    pass

    实举例下:

    >>> name = “Alexissb”
  >>> name.__len__()
  8
  >>> len(name)
  8
    11.count(self,sub,start=None,end=None)
    def count(self, sub, start=None, end=None): # real signature
unknown; restored from __doc__
    ”””
    S.count(sub[, start[, end]]) -> int

        再次回到在字符串中现身钦赐字符的个数,重临二个板寸

    Return the number of non-overlapping occurrences of substring
sub in
    string S[start:end]. Optional arguments start and end are
    interpreted as in slice notation.
    ”””
    return 0

   
count(self,sub,start=None,end=None卡塔尔是用来总括字符串中冒出一定字符的个数,重临贰个整数,实举个例子下:

    >>> name = “Alexssbbafadgcxlsdgpssl”
    >>> name.count(“a”)
  2
    >>> name.count(“D”)
  0
    总括字符串中冒出钦定字符的个数,当一纸空文的时候再次回到0。

    12.encode(self,encoding=’utf-8′,errors=’strict’)

    def encode(self, encoding=’utf-8′, errors=’strict’): # real
signature unknown; restored from __doc__
    ”””
    S.encode(encoding=’utf-8′, errors=’strict’) -> bytes
        编码
    Encode S using the codec registered for encoding. Default
encoding
    is ‘utf-8’. errors may be given to set a different error
    handling scheme. Default is ‘strict’ meaning that encoding
errors raise
    a UnicodeEncodeError. Other possible values are ‘ignore’,
‘replace’ and
    ’xmlcharrefreplace’ as well as any other name registered with
    codecs.register_error that can handle UnicodeEncodeErrors.
    ”””
    return b””

    实比如下:

    >>> name = “李杰”
  >>> name.encode(“gbk”)
  b’\xc0\xee\xbd\xdc’
    将字符串转变为”gbk”格式,机器度和胆识其他格式。

    13.endswith(self,suffix,start=None,end=None)

    def endswith(self, suffix, start=None, end=None): # real signature
unknown; restored from __doc__
    ”””
    S.endswith(suffix[, start[, end]]) -> bool
       
字符串是还是不是以钦点的字符结束,endswith(self,suffix,start=None,end=None卡塔尔(英语:State of Qatar)
    Return True if S ends with the specified suffix, False
otherwise.
    With optional start, test S beginning at that position.
    With optional end, stop comparing S at that position.
    suffix can also be a tuple of strings to try.
    ”””
    return False

   
endswith(self,suffix,start=None,end=None卡塔尔判定字符串以有个别钦点的字符结束,要是是,则赶回布尔值True;不然重回False。

    >>> name = “Alexsssbdfgedlmnopqqsstabsc”
  >>> name.endswith(“c”)
  True
  >>> name.endswith(“s”,0,5)
  True
    14.expandtabs(self,tabsize=8)

    def expandtabs(self, tabsize=8): # real signature unknown; restored
from __doc__
    ”””
    S.expandtabs(tabsize=8) -> str
       
将字符串中的tab键转变为空格,暗中认可时8个职位的空格,能够和谐设置参数
    Return a copy of S where all tab characters are expanded using
spaces.
    If tabsize is not given, a tab size of 8 characters is
assumed.
    ”””
    return “”

   
expandtabs(self,tabsize=8卡塔尔国将字符串中的tab(\t卡塔尔将转速为空格,私下认可是转账为8个空格,能够和睦安装转变为多少个空格。示举个例子下:

    >>> user = ”    Alex”
  >>> user.expandtabs()
  ’        Alex’
  >>> user.expandtabs(2)
  ’  Alex’
  >>> user.expandtabs(0)
  ’Alex’
  >>> user.expandtabs(tabsize=3)
  ’   Alex’
    15.find(self,sub,start=None,end=None)

    def find(self, sub, start=None, end=None): # real signature
unknown; restored from __doc__
    ”””
    S.find(sub[, start[, end]]) -> int
       
查找内定字符在字符串中的位置,再次回到地点索引,假若找寻不到,则赶回-1(return
-1 on failure卡塔尔国
    Return the lowest index in S where substring sub is found,
    such that sub is contained within S[start:end]. Optional
    arguments start and end are interpreted as in slice notation.

    Return -1 on failure.
    ”””
    return 0
   
find(self,sub,start=None,end=None卡塔尔(英语:State of Qatar)查找钦命字符在字符串中的地点,假使搜索不到,则赶回-1(即查找字符不设有钦赐字符串中卡塔尔(英语:State of Qatar),示举个例子下:

    >>> name
  ’Alexsssbdfgedlmnopqqsstabsc’
  >>> name.find(“s”)
  4
  >>> name.find(“s”,8,len(name)-1)
  20
  >>> name.find(“S”)
  -1
   
find(self,sub,start=None,end=None卡塔尔(قطر‎查找这几个字符第一次现身的岗位索引。只查找第多少个任务索引,查找未果重临-1.
    16.index(self,sub,start=None,end=None)

    def index(self, sub, start=None, end=None): # real signature
unknown; restored from __doc__
    ”””
    S.index(sub[, start[, end]]) -> int
       
    Like S.find() but raise ValueError when the substring is not
found.
    ”””
    return 0

     
index(self,sub,start=None,end=None卡塔尔跟find(卡塔尔国一样是搜索钦命字符在字符串中的地点索引,不一样的是,尽管index(卡塔尔国查找未果,则报错。招来不到报错。 
示比方下:

     >>> name
  ’Alexsssbdfgedlmnopqqsstabsc’
  >>> name.index(“s”)
  4
  >>> name.index(“s”,8,len(name)-1)
  20
  >>> name.index(“S”)
  Traceback (most recent call last):
     File “<stdin>”, line 1, in <module>
  ValueError: substring not found    
上面能够看来,index(卡塔尔国和find(卡塔尔(英语:State of Qatar)是同等的,都以回到寻觅字符的职分索引,不过当index(卡塔尔查找不到的时候会报错。

    17.format_map(self,mapping)

    def format_map(self, mapping): # real signature unknown; restored
from __doc__
    ”””
    S.format_map(mapping) -> str

    Return a formatted version of S, using substitutions from
mapping.
    The substitutions are identified by braces (‘{‘ and ‘}’).
    ”””
    return “”

    18.isalnum(self)

    def isalnum(self): # real signature unknown; restored from
__doc__
    ”””
    S.isalnum() -> bool
       判别字符串中装有的字符是还是不是都以字符数字组合
    Return True if all characters in S are alphanumeric
    and there is at least one character in S, False otherwise.
    ”””
    return False
   
示比如下:推断字符串中是否具有因素唯有数字和字母组成,alnum是单词alphanumeric的缩写,字母数字
    >>> name.isalnum()
  True
  >>> nums = “2233”
  >>> nums.isalnum()
  True

    19.isalpha()

    def isalpha(self): # real signature unknown; restored from
__doc__
    ”””
    S.isalpha() -> bool
        判定字符串中具有的成分是还是不是都以字母组成
    Return True if all characters in S are alphabetic
    and there is at least one character in S, False otherwise.
    ”””
    return False

   
判别字符串全数字符是不是都以字母alpha是单词alphabetic(字母)的缩写:  

>>> nums = “2233”
  >>> name.isalpha()
  True
  >>> nums.isalpha()
  False
    20.isdecimal(self)

    def isdecimal(self): # real signature unknown; restored from
__doc__
    ”””
    S.isdecimal() -> bool
       
假如字符串中值包涵十进制的数字,则赶回True;不然重回布尔值False.
    Return True if there are only decimal characters in S,
    False otherwise.
    ”””
    return False

   
isdecimal(self卡塔尔国决断字符串中是或不是只富含十进制的数字,要是是,则赶回True;不然重临False。示比如下:

    >>> s1 = “a122”
  >>> s2 = “222”
  >>> s3 = “&b#s”
  >>> s1.isdecimal()
  False
  >>> s2.isdecimal()
  True
  >>> s3.isdecimal()
  False
    21.isdigit(self)
    def isdigit(self): # real signature unknown; restored from
__doc__
    ”””
    S.isdigit() -> bool
        决断字符串是不是仅仅由数字组合
    Return True if all characters in S are digits
    and there is at least one character in S, False otherwise.
    ”””
    return False

   
isdigit(self卡塔尔(قطر‎决断字符串中是否唯有富含数字,即由数字构成的字符串。实比方下:

    >>> s1 = “a122”
  >>> s2 = “222”
  >>> s3 = “&b#s”

    >>> s1.isdigit()
  False
  >>> s2.isdigit()
  True
  >>> s3.isdigit()
  False
    22.isidentifier(self)

    def isidentifier(self): # real signature unknown; restored from
__doc__
    ”””
    S.isidentifier() -> bool

    Return True if S is a valid identifier according
    to the language definition.

    Use keyword.iskeyword() to test for reserved identifiers
    such as “def” and “class”.
    ”””
    return False

    isidentifier(self卡塔尔(英语:State of Qatar),实比如下:

    >>> s2 = “Alex”
  >>> s3 = “list”
  >>> s2.isidentifier()
  True
  >>> s3.isidentifier()
  True
  >>> s4 = “55”
  >>> s4.isidentifier()
  False
  >>> s5 = “gengcx”
  >>> s5.isidentifier()
  True

    23.islower(self)

    def islower(self): # real signature unknown; restored from
__doc__
    ”””
    S.islower() -> bool
        推断是或不是都以小写
    Return True if all cased characters in S are lowercase and
there is
    at least one cased character in S, False otherwise.
    ”””
    return False

    islower(self卡塔尔(قطر‎剖断字符串是还是不是都以小写,

    >>> s1 = “Alex”
  >>> s2 = “23abc”
  >>> s3 = “alex”
  >>> s4 = “AlexSb&&”
  >>> s5 = “a%@”
  >>> s1.islower()
  False
  >>> s2.islower()
  True
  >>> s3.islower()
  True
  >>> s4.islower()
  False
  >>> s5.islower()
  True
    24.isnumeric(self)

    def isnumeric(self): # real signature unknown; restored from
__doc__
    ”””
    S.isnumeric() -> bool

    Return True if there are only numeric characters in S,
    False otherwise.
    ”””
    return False

   
isnumeric(self卡塔尔国判别字符串S中是还是不是值包涵数字在里面,假诺是,重返True;否则重回False.

    >>> name = “Alex222”
  >>> nums = “234239”
  >>> num = “23se”
  >>> l1 = “2.35”
  >>> name.isnumeric()
  False
  >>> nums.isnumeric()
  True
  >>> num.isnumeric()
  False
  >>> l1.isnumeric()
  False
    25.isprintable(self)

    def isprintable(self): # real signature unknown; restored from
__doc__
    ”””
    S.isprintable() -> bool
      
判别叁个字符串是还是不是里面包车型客车字符都是足以打印出来的照旧字符串是空的,假诺是回去True;不然再次来到False
    Return True if all characters in S are considered
    printable in repr() or S is empty, False otherwise.
    ”””
    return False

    isprintable(self) 

    >>> name = ”    Alex”
  >>> name.isprintable()
  False
  >>> user = “Alex”
  >>> user.isprintable()
  True

    >>> s1 = “”
    >>> s1.isprintable()
  True
    isprintable(s1卡塔尔国中s1是空的字符串,不过也回到True.
    26.isspace(self)

    def isspace(self): # real signature unknown; restored from
__doc__
    ”””
    S.isspace() -> bool
        决断字符串中是不是都是四壁荒疏
    Return True if all characters in S are whitespace
    and there is at least one character in S, False otherwise.
    ”””
    return False

   
isspace(self卡塔尔(英语:State of Qatar)判别字符串中是或不是都是别无长物,尽管是回来True;不然再次来到False。示例如下:

    >>> s1 = ”    “
  >>> s2 = ”       “
  >>> s3 = “cs   “
  >>> s1.isspace()
  True
  >>> s2.isspace()
  True
  >>> s3.isspace()
  False
    27.istitle(self)

    def istitle(self): # real signature unknown; restored from
__doc__
    ”””
    S.istitle() -> bool
        剖断字符串中负有字符是或不是是首字母大写方式,若是是回去True
    Return 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.
    ”””
    return False

   
istitle(self)判断是或不是首字母大写,若是是回去True;不然再次回到False。实举例下:

    >>> s1 = “Alex is sb”
  >>> s2 = “Alex Is Sb”
  >>> s3 = “alex is sb”
  >>> s1.istitle()
  False
  >>> s2.istitle()
  True
  >>> s3.istitle()
  False
    28.isupper(self)

    def isupper(self): # real signature unknown; restored from
__doc__
    ”””
    S.isupper() -> bool
        判别全体字母是或不是都是大写
    Return True if all cased characters in S are uppercase and
there is
    at least one cased character in S, False otherwise.
    ”””
    return False
      isupper(self卡塔尔国判别字符串中全数字符是或不是都是大写方式:实举例下:

    >>> s1 = “Alex is sb”
  >>> s2 = “Alex Is Sb”
    >>> s3 = “alex is sb”

    >>> s4 = “ALEX IS SB”
    >>> s1.isupper()
  False
  >>> s2.isupper()
  False
  >>> s3.isupper()
  False

    >>> s4.isupper()
  True

    29.join(self,iterable)

    def join(self, iterable): # real signature unknown; restored from
__doc__
    ”””
    S.join(iterable) -> str
        字符串的拼凑,把字符串拼接到一齐
    Return a string which is the concatenation of the strings in
the
    iterable. The separator between elements is S.
    ”””
    return “”
   
join(self,iterable卡塔尔(英语:State of Qatar)拼接,字符串和列表直接的拼凑,有两样措施的拼接,上边来商量一下:

    >>> sign = “-“
  >>> name = “alex”
  >>> li = [“a”,”l”,”e”,”x”,”s”,”b”]
  >>> l1 = “”
   
1.字符串和字符串举行拼接,将拼接中的字符串的每一个因素与字符串中的成分进行拼接,即iterable+self+iterable+self… 

  >>sign.join(name)
  ’a-l-e-x’
  >>> name.join(“sb”)
  ’salexb’
  >>> name.join(“issb”)
  ’ialexsalexsalexb’
  2.字符串和列表实行拼接,列表中的每贰个元素都与字符串的成分举行拼接:

  >>> sign.join(li)
  ’a-l-e-x-s-b’
  >>> l1.join(li)
  ’alexsb’

   
其实在Python中,字符串存款和储蓄的格式便是列表存储的,譬如”alexsb”存款和储蓄正是[“a”,”l”,”e”,”x”,”s”,”b”],因此字符串与列表拼接与字符串与字符串拼接是一模二样的。

    30.ljust(self,width,fillchar=None)

    def ljust(self, width, fillchar=None): # real signature unknown;
restored from __doc__
    ”””
    S.ljust(width[, fillchar]) -> str
       固定长度,字符串左侧拼接钦定的字符
    Return S left-justified in a Unicode string of length width.
Padding is
    done using the specified fill character (default is a space).
    ”””
    return “”
    ljust(self,width,fillchar=None卡塔尔国,固定长度,self+fillchar,实例如下:

    >>> name = “alexsb”
    >>> name.ljust(12,”-“)
  ’alexsb——‘

    31.rjust(self,width,fillchar=None)

    def rjust(self, width, fillchar=None): # real signature unknown;
restored from __doc__
    ”””
    S.rjust(width[, fillchar]) -> str

    Return S right-justified in a string of length width. Padding
is
    done using the specified fill character (default is a space).
    ”””
    return “”
    固定字符串长度,在字符串侧边链接钦点字符,实举个例子下:

    >>> name = “alexsb”   

  >>> name.rjust(12,”-“)
  ’——alexsb’

    32.lower(self)

    def lower(self): # real signature unknown; restored from
__doc__
    ”””
    S.lower() -> str
        将字符串全体倒车为小写情势
    Return a copy of the string S converted to lowercase.
    ”””
    return “”
    33.lstrip(self,chars=None)

    def lstrip(self, chars=None): # real signature unknown; restored
from __doc__
    ”””
    S.lstrip([chars]) -> str

    Return a copy of the string S with leading whitespace
removed.
    If chars is given and not None, remove characters in chars
instead.
    ”””
    return “”
   
lstrip(self,chars=None卡塔尔(قطر‎是删除字符串侧边的空格,暗中同意是剔除空格,其实能够钦定删除任何字符,实譬喻下:

    >>> name = ”   AlexAesbb   “
  >>> name.lstrip()
  ’AlexAesbb   ‘

    34.rstrip(self,chars=None)

    def rstrip(self, chars=None): # real signature unknown; restored
from __doc__
    ”””
    S.rstrip([chars]) -> str
        删除字符串左边的空格
    Return a copy of the string S with trailing whitespace
removed.
    If chars is given and not None, remove characters in chars
instead.
    ”””
    return “”
    rstrip(self,chars=None卡塔尔删除字符串侧边的空格,实比方下:

    >>> name = ”   AlexAesbb   ”   

    >>> name.rstrip()
‘   AlexAesbb’

    35.strip(self,chars=None)

    def strip(self, chars=None): # real signature unknown; restored
from __doc__
    ”””
    S.strip([chars]) -> str

    Return a copy of the string S with leading and trailing
    whitespace removed.
    If chars is given and not None, remove characters in chars
instead.
    ”””
    return “”
     strip(self,chars=None卡塔尔国删除字符串两边的空格,示举例下:

    >>> name = ”   AlexAesbb   ”   

    >>> name.strip()
  ’AlexAesbb’

    36.maketrans(self,*args,**kwargs)

    def maketrans(self, *args, **kwargs): # real signature unknown
    ”””
    Return a translation table usable for str.translate().

    If there is only one argument, it must be a dictionary mapping
Unicode
    ordinals (integers) or characters to Unicode ordinals, strings
or None.
    Character keys will be then converted to ordinals.
    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.
    ”””
    pass
    37.translate(self,table)

    def translate(self, table): # real signature unknown; restored from
__doc__
    ””
    S.translate(table) -> str

    Return a copy of the string S in which each character has been
mapped
    through the given translation table. The table must implement
    lookup/indexing via __getitem__, for instance a dictionary
or list,
    mapping Unicode ordinals to Unicode ordinals, strings, or None.
If
    this operation raises LookupError, the character is left
untouched.
    Characters mapped to None are deleted.
    ”””
    return “”
    示举例下:

    >>> intab = “aeiou”
  >>> outtab = “12345”

    >>> trantab = intab.maketrans(intab,outtab)
  >>> trantab
  {97: 49, 111: 52, 117: 53, 101: 50, 105: 51}

    >>> str = “This is string example …. wow!!!”
    >>> str.translate(trantab)
  ’Th3s 3s str3ng 2x1mpl2 …. w4w!!!’

   
上边代码含义是,把intab中种种成分与outtab中每种成分大器晚成生龙活虎对应,然后translate(卡塔尔替换个中对应的要素。

    38.partition(self,sep)

    def partition(self, sep): # real signature unknown; restored from
__doc__
    ”””
    S.partition(sep) -> (head, sep, tail)
        字符串分隔,以sep分隔为前中后三有个别
    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.
    ”””
    pass
   
partition(self,sep卡塔尔国字符串分隔,以字符串sep分隔为前中后三部分,何况以找到的率先个字符为分隔:

    >>> name = ‘   AlexAesbb   ‘
  >>> name.partition(“x”)
  (‘   Ale’, ‘x’, ‘Aesbb   ‘)
  >>> name.partition(“A”)
  (‘   ‘, ‘A’, ‘lexAesbb   ‘)

    39.replace(self,old,new,count=None)

    def replace(self, old, new, count=None): # real signature unknown;
restored from __doc__
    ”””
    S.replace(old, new[, count]) -> str
        字符串的索求替换
    Return a copy of S with all occurrences of substring
    old replaced by new. If the optional argument count is
    given, only the first count occurrences are replaced.
    ”””
    return “”
   
字符串的退换,old哪个字符要替换,new替换到什么样,count替换多少个,实比方下:

    >>> name = ‘   AlexAesbb   ‘
  >>> name.replace(“A”,”M”)
  ’   MlexMesbb   ‘
  >>> name.replace(“A”,”M”,1)
  ’   MlexAesbb   ‘

    字符串的检索替换,暗中认可替换全体,能够钦命替换的个数。

    39.rfind(self,sub,start=None,end=None)

    def rfind(self, sub, start=None, end=None): # real signature
unknown; restored from __doc__
    ”””
    S.rfind(sub[, start[, end]]) -> int
        从侧面开首查找
    Return the highest index in S where substring sub is found,
    such that sub is contained within S[start:end]. Optional
    arguments start and end are interpreted as in slice notation.

    Return -1 on failure.
    ”””
    return 0
    从字符串左边发轫查找,查找钦命字符在字符串中的地点索引:实比方下:

    >>> name = ‘   AlexAesbb   ‘
  >>> name.rfind(“A”)
  7
  >>> name.find(“A”)
  3
  >>> name.rfind(” “)
  14

    从侧面查找钦赐字符在字符串中之处索引,假使寻找不到重返-1.

    40.rindex(self,sub,start=None,end=None)

    def rindex(self, sub, start=None, end=None): # real signature
unknown; restored from __doc__
    ”””
    S.rindex(sub[, start[, end]]) -> int

    Like S.rfind() but raise ValueError when the substring is not
found.
    ”””
    return 0
   
rindex(self,sub,start=None,end=None卡塔尔(英语:State of Qatar)从字符串侧面查找钦赐字符的岗位索引,要是搜索不到就能够报错。

    41.rpartition(self,sep)

    def rpartition(self, sep): # real signature unknown; restored from
__doc__
    ”””
    S.rpartition(sep) -> (head, sep, tail)
        从字符串左边起先查找分隔
    Search for the separator sep in S, starting at the end of S,
and return
    the part before it, the separator itself, and the part after
it. If the
    separator is not found, return two empty strings and S.
    ”””
    pass
   
rpartition(self,sep卡塔尔(英语:State of Qatar)从字符串侧边开头查找分隔,与partition(self,sep卡塔尔(英语:State of Qatar)刚巧相反,示举例下,分隔字符串得到一个元组:

    >>> name = ‘   AlexAesbb   ‘
  >>> name.partition(“A”)
  (‘   ‘, ‘A’, ‘lexAesbb   ‘)
  >>> name.rpartition(“A”)
  (‘   Alex’, ‘A’, ‘esbb   ‘)

    42.rsplit(self,sep=None,maxsplit=-1)

    def rsplit(self, sep=None, maxsplit=-1): # real signature unknown;
restored from __doc__
    ”””
    S.rsplit(sep=None, maxsplit=-1) -> list of strings

    Return a list of the words in S, using sep as the
    delimiter string, starting at the end of the string and
    working to the front. If maxsplit is given, at most maxsplit
    splits are done. If sep is not specified, any whitespace
string
    is a separator.
    ”””
    return []
   
rsplit(self,sep=None,maxsplit=-1卡塔尔分隔字符串,并转移贰个存放的列表,实比方下:

    >>> name = “Alexsbegcex”
  >>> name.split(“e”)
  [‘Al’, ‘xsb’, ‘gc’, ‘x’]
  >>> name.rsplit(“e”)
  [‘Al’, ‘xsb’, ‘gc’, ‘x’]

    >>> name.split(“e”,0)
  [‘Alexsbegcex’]
  >>> name.split(“e”,1)
  [‘Al’, ‘xsbegcex’]
  >>> name.split(“e”,2)
  [‘Al’, ‘xsb’, ‘gcex’]
  >>> name.split(“e”,3)
  [‘Al’, ‘xsb’, ‘gc’, ‘x’]
  >>> name.split(“e”,4)
  [‘Al’, ‘xsb’, ‘gc’, ‘x’]
  >>> name.split(“e”,-1)
  [‘Al’, ‘xsb’, ‘gc’, ‘x’]

   
以钦点字符串分隔,並且替换内定字符,分隔产生一个列表,能够钦命分隔字符的个数。

    43.split(self,sep=None,maxsplit=-1)

    def split(self, sep=None, maxsplit=-1): # real signature unknown;
restored from __doc__
    ”””
    S.split(sep=None, maxsplit=-1) -> list of strings
        分隔字符串,生成叁个列表,可以钦定分隔的次数,默许是任何相间
    Return a list of the words in S, using sep as the
    delimiter string. If maxsplit is given, at most maxsplit
    splits are done. If sep is not specified or is None, any
    whitespace string is a separator and empty strings are
    removed from the result.
    ”””
    return []
    44.splitlines(self,keepends=None)

    def splitlines(self, keepends=None): # real signature unknown;
restored from __doc__
    ”””
    S.splitlines([keepends]) -> list of strings

    Return a list of the lines in S, breaking at line boundaries.
    Line breaks are not included in the resulting list unless
keepends
    is given and true.
    ”””
    return []
   
splitlines(self,keepends=None)以”\n”换行符的花样分隔字符串,实举例下:

    >>> user = “””
  … alex
  … aoi
  … marry”””

    >>> user.splitlines()
  [”, ‘alex’, ‘aoi’, ‘marry’]

    45.startswith(self,prefix,start=None,end=None)

    def startswith(self, prefix, start=None, end=None): # real
signature unknown; restored from __doc__
    ”””
    S.startswith(prefix[, start[, end]]) -> bool
        字符串是或不是以钦赐字符开首,能够钦命早先地点
    Return True if S starts with the specified prefix, False
otherwise.
    With optional start, test S beginning at that position.
    With optional end, stop comparing S at that position.
    prefix can also be a tuple of strings to try.
    ”””
    return False
   
startswith(self,prefix,start=None,end=None卡塔尔(قطر‎剖断字符串是还是不是以钦点字符最早,可以内定最早地方,与endswith(self,prefix,start=None,end卡塔尔

赶巧相反,示比方下:

    >>> name = ‘Alexsbegcex’
    >>> name.startswith(“A”)
  True
    >>> name.startswith(“w”)
  False

    >>> name.startswith(“e”,2,5)
  True

    46.swapcase(self)

    def swapcase(self): # real signature unknown; restored from
__doc__
    ”””
    S.swapcase() -> str
        将一个字符串中保有大写字符转换为小写,小写转变为题写
    Return a copy of S with uppercase characters converted to
lowercase
    and vice versa.
    ”””
    return “”
   
swapcase(self卡塔尔(英语:State of Qatar)将二个字符串中具有字符小写转变为大写,大写转化为小写,好贱呀那一个办法,实举个例子下:

    >>> name = ‘Alexsbegcex’
  >>> name.swapcase()
  ’aLEXSBEGCEX’

    47.title(self)

    def title(self): # real signature unknown; restored from
__doc__
    ”””
    S.title() -> str
        将字符串首字母转变为题写
    Return a titlecased version of S, i.e. words start with title
case
    characters, all remaining cased characters have lower case.
    ”””
    return “”
    48.upper(self)

    def upper(self): # real signature unknown; restored from
__doc__
    ”””
    S.upper() -> str
        将字符串全数字母都改造为题写
    Return a copy of S converted to uppercase.
    ”””
    return “”
    49.zfill(self,width)

    def zfill(self, width): # real signature unknown; restored from
__doc__
    ”””
    S.zfill(width) -> str
        钦命宽度,不足左边补零
    Pad a numeric string S with zeros on the left, to fill a
field
    of the specified width. The string S is never truncated.
    ”””
    return “”
    zfill(self,width卡塔尔(قطر‎钦命宽度,不足左边补0,不然不改变。实比如下:

    >>> name = ‘Alexsbegcex’
  >>> name.zfill(20)
  ’000000000Alexsbegcex’
  >>> name.zfill(5)
  ’Alexsbegcex’
    50.__contains__(self,*args,**kwargs)

    def __contains__(self, *args, **kwargs): # real signature
unknown
    ””” Return key in self. “””

        剖断字符串中是还是不是带有钦点字符
    pass
   
__contains__(self,*args,**kwargs卡塔尔判别字符串中是不是带有钦定字符,实比方下:

    >>> name = ‘Alexsbegcex’
  >>> name.__contains__(“e”)
  True
  >>> name.__contains__(“E”)
  False

   
 

 

字符串是编制程序中常用的项目,字符型在内存中是以单个格局积攒的,举例name =
“alex”,在内存中蕴藏的样式为…

语法

find(卡塔尔(英语:State of Qatar)方韩文法:

str.find(str, beg=0, end=len(string))

 

语法

casefold(卡塔尔(英语:State of Qatar)方阿尔巴尼亚语法:

S.casefold()

 

参数

  • tabsize — 钦定转换字符串中的 tab 符号(‘\t’卡塔尔转为空格的字符数。

参数

  • str — 钦定检索的字符串
  • beg — 开头索引,默以为0。
  • end — 甘休索引,暗中认可为字符串的长度。

返回值

回到将字符串中颇有大写字符转换为小写后变化的字符串。

返回值

该措施重回字符串中的 tab 符号(‘\t’卡塔尔转为空格后生成的新字符串。

返回值

假诺含有子字符串重临初叶的索引值,不然重临-1。

实例

以下实例体现了casefold(卡塔尔(قطر‎方法的实例:

#!/usr/bin/python3

S1 = "Runoob EXAMPLE....WOW!!!" #英文
S2 = "ß"  #德语

print( S1.lower() )
print( S1.casefold() )
print( S2.lower() )
print( S2.casefold() ) #德语的"ß"正确的小写是"ss"

  

上述实例输出结果如下:

runoob example....wow!!!
runoob example....wow!!!
ß
ss

 

实例

以下实例呈现了expandtabs(卡塔尔(قطر‎方法的实例:

#!/usr/bin/python3

str = "this is\tstring example....wow!!!"

print ("原始字符串: " + str)
print ("替换 \\t 符号: " +  str.expandtabs())
print ("使用16个空格替换 \\t 符号: " +  str.expandtabs(16))

上述实例输出结果如下:

原始字符串: this is     string example....wow!!!
替换 \t 符号: this is string example....wow!!!
使用16个空格替换 \t 符号: this is         string example....wow!!!

 

实例

以下实例显示了find(卡塔尔(英语:State of Qatar)方法的实例:

#!/usr/bin/python3

str1 = "Runoob example....wow!!!"
str2 = "exam";

print (str1.find(str2))
print (str1.find(str2, 5))
print (str1.find(str2, 10))

 

如上实例输出结果如下:

7
7
-1

实例

>>>info = 'abca'
>>> print(info.find('a'))      # 从下标0开始,查找在字符串里第一个出现的子串,返回结果:0
0
>>> print(info.find('a', 1))   # 从下标1开始,查找在字符串里第一个出现的子串:返回结果3
3
>>> print(info.find('3'))      # 查找不到返回-1
-1
>>>

 

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