str字符串常用方法,str字符串

by admin on 2019年12月3日

描述

find(卡塔尔国 方法检查评定字符串中是或不是带有子字符串 str ,即使钦命 beg(最早) 和
end(结束)
范围,则检查是否满含在钦点范围内,借使钦赐范围内假设含有钦赐索引值,再次来到的是索引值在字符串中的初阶地点。若是不包含索引值,再次回到-1。

str字符串常用方法,str字符串

Python字符串str的办法运用,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表示:’123′,”abc”,”字符串”
#str字符串…

描述

Python
casefold(卡塔尔国方法是Python3.3版本之后引进的,其功用和 lower() 方法拾贰分相仿,都得以转换字符串中颇有大写字符为小写。

三头的分别是:lower(卡塔尔(英语:State of Qatar)方法只对ASCII编码,也正是‘A-Z’有效,对于其他语言(非汉语或Hungary语)中把大写转变为小写的事态只好用
casefold(卡塔尔(英语:State of Qatar) 方法。

描述

Python capitalize(卡塔尔将字符串的第八个假名产生大写,其余字母变小写。

语法

find(卡塔尔国方英语法:

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

 

    字符串是编制程序中常用的连串,字符型在内部存款和储蓄器中是以单个情势储存的,举例name

“alex”,在内部存款和储蓄器中积攒的款型为[“a”,”l”,”e”,”x”],因而我们能够运用列表的许多功能来操作字符串,因为本人起来的时候一贯在想怎么字符串能够动用切块,能够有目录,起先的时候向来不领会,后来掌握了Python字符串的仓储方式之后才通晓怎么存在这里些艺术。上边大家来探视字符串类型中含有那一个方法:

   
在Python中微微措施上边有注释,这是因为那个格局运用Python自个儿编写的,大家知晓Python中好多是直接调用C语言中的方法,看不到的那一个是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,只是第二个居首第一个首字母大写
    Return a capitalized version of S, i.e. make the first
character
    have upper case and the rest lower case.
    ”””
    return “”

   
capitalize(self卡塔尔国是位居第二位首字母大写,大家知晓还会有多少个方法title(卡塔尔,下边来相比这四个法子的差别点:

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

   
从地方能够看出,capitalize(self卡塔尔国是居首首字母大写,其余字母超小写;而title(self卡塔尔(英语:State of Qatar)方法是有着单词的首字母都大写,这么些在用的时候要清楚是讲求那么字母大写。

    2.casefold(self)

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

    casefold(self卡塔尔国是将大写字母转变为小写,等价于lower(self卡塔尔国,实举例下:

    >>> 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卡塔尔国是将字符串放到中间,两边加上狂妄符号,私下认可空格”””
    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(قطر‎,美化格式,把self放到中间,钦赐大肆长度的字符,空白处用字符填充,暗许时间和空间字符。示比方下:

    >>> 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卡塔尔国字符串进行格式化,根据大家要求的格式进行字符串格式化操作。详细可参照他事他说加以考查()

    >>> 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.’
   
这种方法也能够用在字符串的拼凑下面,使用字符串的format(卡塔尔(英语:State of Qatar)方法,在{}大括号中定义索引,告诉Python把哪些值传给索引地点。

    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]. “””

    ”””拿到字符串低等个因素,等价于self[key]”””
    pass  

   
正是赢得字符串中第多少个职位的字符,大家通晓字符串在内存中是以列表方式储存的,由此得以使用索引来获取单个字符,实比方下:

    >>> name = “Alexissb”
  >>> name.__getitem__(2)
  ’e’
  >>> name[2]
  ’e’
    字符串中索引是从0开头的,获取字符串中第多少个岗位的字符。

    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). “””

        “””重临字符串的尺寸,等价与len(self卡塔尔国”””
    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

        重返在字符串中冒出钦命字符的个数,重回叁个整数

    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(قطر‎是用来总结字符串中现身一定字符的个数,重回三个大背头,实举例下:

    >>> name = “Alexssbbafadgcxlsdgpssl”
    >>> name.count(“a”)
  2
    >>> name.count(“D”)
  0
    总计字符串中现身钦命字符的个数,当不设有的时候重回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””

    实举个例子下:

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

    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定的字符截止,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(英语:State of Qatar)判定字符串以有个别钦赐的字符停止,借使是,则赶回布尔值True;不然再次回到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,私下认可时8个职分的空格,能够本身安装参数
    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卡塔尔将字符串中的tab(\t卡塔尔国将转速为空格,私下认可是转载为8个空格,能够本人设置转化为多少个空格。示举例下:

    >>> 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地点,再次回到地方索引,假诺搜索不到,则赶回-1(return
-1 on failure卡塔尔(قطر‎
    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(قطر‎查找钦点字符在字符串中的地点,如若搜索不到,则赶回-1(即查找字符不设有钦赐字符串中卡塔尔(قطر‎,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卡塔尔国查找那几个字符第叁回面世之处索引。只查找第二个岗位索引,查找未果再次回到-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(英语:State of Qatar)跟find(卡塔尔(英语:State of Qatar)同样是查究钦点字符在字符串中之处索引,分歧的是,借使index(卡塔尔(قطر‎查找未果,则报错。探究不到报错。 
示比如下:

     >>> 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    
上面能够看见,index(卡塔尔(英语:State of Qatar)和find(卡塔尔(英语:State of Qatar)是千篇黄金时代律的,都以回来搜索字符之处索引,但是当index(卡塔尔(قطر‎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
       判别字符串中全部的字符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
   
示举例下:剖断字符串中是否有所因素唯有数字和字母组成,alnum是单词阿尔法numeric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
        判定字符串中兼有的要素是或不是都是字母组成
    Return True if all characters in S are alphabetic
    and there is at least one character in S, False otherwise.
    ”””
    return False

   
推断字符串全体字符是或不是都以字母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
       
若是字符串中值蕴涵十进制的数字,则赶回True;不然再次回到布尔值False.
    Return True if there are only decimal characters in S,
    False otherwise.
    ”””
    return False

   
isdecimal(self卡塔尔(قطر‎判定字符串中是还是不是只富含十进制的数字,倘使是,则赶回True;不然再次回到False。示比方下:

    >>> 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
        判别字符串是还是不是只是由数字组成
    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(英语:State of Qatar)判定字符串中是不是仅仅包蕴数字,即由数字构成的字符串。实举个例子下:

    >>> 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卡塔尔国,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
        剖断是不是都以小写
    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卡塔尔判别字符串S中是还是不是值包蕴数字在里边,如若是,再次回到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
      
推断一个字符串是不是里面的字符都以足以打字与印刷出来的只怕字符串是空的,若是是重返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
        判定字符串中是或不是都以单手
    Return True if all characters in S are whitespace
    and there is at least one character in S, False otherwise.
    ”””
    return False

   
isspace(self卡塔尔剖断字符串中是还是不是都以白手,借使是回到True;不然重返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
        决断字符串中颇具字符是不是是首字母大写方式,借使是重临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)看清是还是不是首字母大写,若是是重临True;不然再次回到False。实比如下:

    >>> 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
        决断全部字母是否都以大写
    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(قطر‎决断字符串中有着字符是或不是都是大写情势:实比如下:

    >>> 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,把字符串拼接到一同
    Return a string which is the concatenation of the strings in
the
    iterable. The separator between elements is S.
    ”””
    return “”
   
join(self,iterable卡塔尔国拼接,字符串和列表直接的拼接,有不一致方法的拼接,上面来研讨一下:

    >>> sign = “-“
  >>> name = “alex”
  >>> li = [“a”,”l”,”e”,”x”,”s”,”b”]
  >>> l1 = “”
   
1.字符串和字符串进行拼接,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.字符串和列表进行拼接,列表中的每多少个要素都与字符串的成分实行拼接:

  >>> 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正是列表存款和储蓄的,譬喻”alexsb”存款和储蓄便是[“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如出风华正茂辙的。

    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,字符串侧边拼接钦命的字符
    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,实比如下:

    >>> 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,在字符串侧面链接内定字符,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
        将字符串全体转会为小写情势
    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卡塔尔是删除字符串侧面的空格,暗中同意是剔除空格,其实能够钦定删除任何字符,实举例下:

    >>> 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
        删除字符串侧边的空格
    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(قطر‎删除字符串侧边的空格,实譬喻下:

    >>> 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,示比如下:

    >>> 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 “”
    示比如下:

    >>> 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中各类成分与outtab中每种成分黄金时代后生可畏对应,然后translate(卡塔尔替换此中对应的要素。

    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分隔为前中后三有些
    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卡塔尔字符串分隔,以字符串sep分隔为前中后三有个别,并且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
        字符串的研究替换
    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 “”
   
字符串的替换,old哪个字符要替换,new替换到什么样,count替换多少个,实举例下:

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

    字符串的搜索替换,暗中同意替换全体,能够钦赐替换的个数。

    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
        从侧面早先查找
    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
    从字符串侧面开头查找,查找内定字符在字符串中之处索引:实举例下:

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

    从左侧查找内定字符在字符串中之处索引,假若搜索不到重返-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卡塔尔国从字符串左边查找内定字符的地点索引,如若寻觅不到就能够报错。

    41.rpartition(self,sep)

    def rpartition(self, sep): # real signature unknown; restored from
__doc__
    ”””
    S.rpartition(sep) -> (head, sep, tail)
        从字符串左侧起初查找分隔
    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卡塔尔从字符串侧边伊始查找分隔,与partition(self,sep卡塔尔(قطر‎正巧相反,示举例下,分隔字符串拿到叁个元组:

    >>> 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(قطر‎分隔字符串,并转移一个存放的列表,实举个例子下:

    >>> 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’]

   
以钦赐字符串分隔,并且替换钦命字符,分隔造成二个列表,能够内定分隔字符的个数。

    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,生成三个列表,能够钦赐分隔的次数,私下认可是整个相间
    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”换行符的款式分隔字符串,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
        字符串是还是不是以钦定字符初叶,能够钦命最初地点
    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卡塔尔推断字符串是不是以钦赐字符开头,能够钦赐早先地点,与endswith(self,prefix,start=None,end卡塔尔(قطر‎

恰恰相反,示比如下:

    >>> 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
        将叁个字符串中有着大写字符转变为小写,小写转变为题写
    Return a copy of S with uppercase characters converted to
lowercase
    and vice versa.
    ”””
    return “”
   
swapcase(self卡塔尔国将三个字符串中具有字符小写转变为大写,大写转变为小写,好贱呀这些艺术,实比如下:

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

    47.title(self)

    def title(self): # real signature unknown; restored from
__doc__
    ”””
    S.title() -> str
        将字符串首字母转换为题写
    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
        将字符串所有字母都改动为题写
    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
        钦赐宽度,不足左侧补零
    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(英语:State of Qatar)钦点宽度,不足左边补0,不然不改变。实举个例子下:

    >>> 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. “””

        判别字符串中是或不是含有钦定字符
    pass
   
__contains__(self,*args,**kwargs卡塔尔剖断字符串中是还是不是含有钦点字符,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品种,字符型在内部存款和储蓄器中是以单个形式累积的,比方name =
“alex”,在内部存款和储蓄器中蕴藏的情势为…

语法

casefold(卡塔尔(英语:State of Qatar)方Türkiye Cumhuriyeti语法:

S.casefold()

 

语法

capitalize(卡塔尔国方保加利亚语法:

str.capitalize()

参数

  • str — 内定检索的字符串
  • beg — 开始索引,默以为0。
  • end — 停止索引,默以为字符串的长短。

返回值

归来将字符串中具有大写字符转换为小写后改变的字符串。

返回值

该办法再次来到七个首字母大写的字符串。

返回值

假使含有子字符串重返初叶的索引值,不然重返-1。

实例

以下实例展现了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

以下实例体现了capitalize(卡塔尔方法的实例:

#!/usr/bin/python3

me = “this is string”

print(“me.capitalize(): “,me.capitalize

上述实例输出结果如下:

me.capitalize():  This is string

实例

以下实例体现了find(卡塔尔(قطر‎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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