1.center,rjust,ljust,zfill
String. Center (length, padding character)
String. Rjust (length, padding character)
String. Ljust (length, padding character)
String. Zfill (length)
str1='ab' print(str1.center(9,'1')) # 11abc111 print(str1.rjust(10,'%')) # %%%%%%%%ab print(str1.zfill(4)) # 00ab # When the length is less than the string length, the original string is output print(str1.zfill(1)) # ab print('abc'.rjust(2,'#')) # abc print('abc'.ljust(2,'#')) # abc
2.count
String 1. Count (string 2) - counts the number of occurrences of string 2 in string 1
String 1. Count (string 2, start subscript, end subscript) ---- the range can be specified, and the following table can be ended at the start subscript ~ end subscript
str1='ab' print(str1.count('ab')) # 1 message='you see see , one day day' print(message.count('a')) # 2 print(message.count('d',-7,-2)) # 2 print(message.count('d',-4)) # 1
3.find and index ---- find rfind and rindex from right to left
# String 1. Find (string 2) -- the position where string 2 first appears in string 1 # String 1. Index (string 2) -- the position where string 2 first appears in string 1 message='you see see , one day day' print(message.find('see')) # 4 print(message.index('see')) # 4 # # When the string 2 is not found, it returns different, find returns - 1, and index reports an error print(message.find('abc')) # -1 # print(message.index('abc')) # ValueError: substring not found print(message.rfind('see')) # 8 print(message.rindex('see')) # 8 print(message.rfind('are')) # -1
4.isalnum,isalpha,isdigit,isnumeric,isspace,isupper,islower
a. String. isalnum() --- judge whether the string contains only numbers, letters and Chinese
b. String. isalpha() -- judge whether the string contains only letters and Chinese
c. String. isdigit() - determines whether the string is a pure numeric string (numeric character)
d. String. isnumeric -- judge whether the string is a pure numeric string (the character of a number in meaning)
e. String. isspace() -- judge whether the string is a blank character
f. String. isupper() -- judge whether all letters in the string are uppercase letters
g. String. islower() -- judge whether all letters in the string are lowercase letters
All return values are Boolean
5. String. Join (sequence) -- merge the elements in the sequence into a new string through the specified string (all elements in the sequence must be strings)
# Exercise: you have created a list. Use '= =' to connect all strings in the list into a new string list1 = [100, 'abc', True, 'Hello', 'hello', 12.9] # 'abc = = hello = = hello' result='=='.join([x for x in list1 if type(x)==str]) print(result)
6.strip,lstrip,rstrip -- remove whitespace on both sides of the string
main_str =' abc123 ' print(main_str,';',sep='')# ' abc123 ;' print(main_str.strip(),';',sep='') # 'abc123;' print(main_str.lstrip(),';',sep='')# 'abc123 ;' print(main_str.rstrip(),';',sep='') # ' abc123;'
7.maketrans,translate
Str.maketrans (string 1, string 2) -- create the corresponding table of string 1 and string 2
String. Translate (corresponding table) -- replace according to the corresponding table
message='Today's Wednesday, tomorrow's Thursday and Friday will be off, and you can go out on Saturday' table=str.maketrans('0123456','123456') result=message.translate(table) print(result) # Today, Thursday, tomorrow, Friday, Saturday will be off, and you can go out on Sunday
8.split
String 1. Split (string 2) -- cut all strings 2 in string 1 as cutting points
result='abcand123andmn'.split('and') print(result) # ['abc', '123', 'mn']
String 1. Split (string 2,N) -- take the first N string 2 as the cutting point
result='abcMN123MNllasdMN'.split('MN',2) print(result) # ['abc', '123', 'llasdMN']
9.replace
String 1. Replace (string 2, string 3) - replaces string 2 in string 1 with string 3
message='abcMN123MNllasdMN' print(message.replace('MN','Hello')) # abc Hello 123 Hello llasd hello
String 1. Replace (string 2, string 3,N) - replaces the first N string 2 in string 1 with string 3
message='abcMN123MNllasdMN' print(message.replace('MN','Hello',2)) # abc Hello 123 Hello llasdMN