Python Basics (str Class)

Second, string (str Class)

Tip: All of the following methods are methods in the class, the first argument is self, and unity is not written.

The methods that are included are:

1, capitalize () #首字母变大写

>>> name= ' Hello World '

>>> name.capitalize ()

' Hello World '

2, center (width, fillchar=none)#内容居中, Width: total length; Fillchar: padding content in white space, default None

>>> name= ' Hello World '

>>> Name.center (20, ' # ')

' # # # #hello world##### '

3, COUNT (X,start=none, End=none)#子序列x的个数 parameters can be connected to start and end positions

>>> name= ' ABCDD '

>>> name.count (' d ', 0,9)

2

>>> name.count (' d ', 0, 3)

0

>>> name.count (' d ', 0,4)

1

4. Find (X,start=none, end=none)#查找子序列x的位置, returns 1 if not found

>>> name= ' ABCD '

>>> name.find (' a ')

0

>>> name.find (' d ')

3

>>> name.find (' e ')

-1

5, index (X,start=none, end=none)#查找子序列x的位置, if not found the exception

>>> Name.index (' a ')

0

>>> Name.index (' d ')

3

>>> name.index (' e ')

Traceback (most recent):

File "<stdin>", line 1, in <module>

Valueerror:substring not found

6, EndsWith (x)#是否以x结束

>>> name= ' ABCD '

>>> name.endswith (' a ')

False

>>> name.endswith (' d ')

True

7, StartsWith (x)#是否以x开始

>>> name= ' ABCD '

>>> name.startswith (' a ')

True

>>> name.startswith (' d ')

False

8, Expandtabs (tabsize=none)#将tab转换成空格, the default tab is converted to 8 spaces

>>> name= ' AB CD '

>>> Name.expandtabs (4)

' AB CD '

9. Format ()#字符串格式化, 4 ways

9-1:

Str1= ' I am {0}, age {1} '

Str1.format (' Alex ', 24)

9-2:

Str2= ' I am {SS}, age {DD} '

Str2.format (ss= ' Alex ', dd=24)#类似于函数的形参

9-3:

li=[' Alex ', 24]

Str3= ' I am {0}, age {1} '

Str3.format (*li)#列表的元素个数必须和需要的参数相等

9-4:

dic={' SS ': Alex, ' DD ': 24}

Str4= ' I am {SS}, age {DD} '

Str4.format (**dic)#字典的key必须和形参的名称一致

10, Isalnum ()#是否是字母和数字

>>> name= ' ABCD '

>>> Name.isalnum ()

True

11, Isalpha ()#是否是字母

>>> name= ' ABCD '

>>> Name.isalpha ()

True

12, IsDigit ()#是否是数字

>>> name= ' ABCD '

>>> Name.isdigit ()

False

13, Islower ()#是否小写 Lower () is to change uppercase in a string to lowercase

>>> name= ' ABCD '

>>> Name.islower ()

True

>>> name= ' ABCD '

>>> Name.islower ()

False

14, Isupper ()#是否是大写 Upper () is to capitalize the lowercase in the string

>>> name= ' ABCD '

>>> Name.isupper ()

False

>>> name= ' ABCD '

>>> Name.isupper ()

True

15, Istitle ()#是否是标题 title () is to set the string as the title, that is, the first letter of each word capitalized

>>> name= ' Hello World '

>>> Name.istitle ()

False

16, Isspace ()#是否是空格

>>> name= '

>>> Name.isspace ()

True

17. Join ()#连接 Returns a string, in contrast to split

>>> name= ' ABCD '

>>> ' _ '. Join (name)

' A_b_c_d '

>>> name=[' A ', ' B ', ' C ', ' d ']

>>> ' _ '. Join (name)

' A_b_c_d '

18, Split (Sep,maxsplit=none)#分割, maxsplit up a few times, the default is full split, the return value is a list

>>> name= ' a,b,c,d '

>>> name.split (', ')#全分割

[' A ', ' B ', ' C ', ' d ']

>>> name.split (', ', 2)#只分割前两个字符串

[' A ', ' B ', ' c,d ']

19, Ljust (width, fillchar=none)#内容左对齐, width is wide, the right padding the specified character, fillchar default is empty rjust () is right-aligned, syntax format

>>> name= ' ABCD '

>>> Name.ljust (20, ' # ')

' abcd################

20, Lstrip ()#移除左侧空白 rstrip () Remove the right blank strip () remove both sides of the blank

>>> name= ' ABCD '

>>> Name.lstrip ()

' ABCD '

>>> Name.rstrip ()

' ABCD '

>>> Name.strip ()

' ABCD '

21. Partition (Sep)#以sep为分割点 Division, before, in, and after three parts

>>> name= ' abc '

>>> name.partition (' B ')

(' A ', ' B ', ' C ')

22, replace (old,new,count=none)#替换, the Count parameter is the specified number of replacements, the default is all replace

>>> name= ' ABCD '

>>> name.replace (' A ', ' e ')

' EBCD '

>>> name= ' 1122334444 '

>>> name.replace (' 4 ', ' 5 ', 2)#替换2个4

' 1122335544 '

>>> name.replace (' 4 ', ' 5 ', 3)#替换3个4

' 1122335554

23, Swapcase ()#大写变小写, lowercase to uppercase

>>> name= ' ABCD '

>>> Name.swapcase ()

' AbCD '

24, translate (table, Deletechars=none)#字符转换, you need to make a corresponding table table,deletechars default is empty, if a character is specified, the specified character will be deleted

Import string

Intab = "Aeiou"

Outtab = "12345"

Trantab = String.maketrans (Intab, Outtab)

STR1 = "This is string EXAMPLE....WOW!!!"

Print str.translate (Trantab, ' XM ')#str1中的含有转换表中的字符都会被转换, the X and M characters will be deleted.

Output result: th3s 3s str3ng 21pl2....w4w!!!

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Lists (List Class)

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Python Basics (str Class)