String or string （String） It's numbers 、 Letter 、 A string of characters made up of underscores . stay Python in , The string is enclosed in single quotation marks or double quotation marks .

Catalog

String splicing

String processing (8 Common use )

String splicing

Put together a comma , Then a space will appear in the comma .

Use the plus sign to splice , There are no spaces . If you want spaces , Then a space should be added

print("Hello","World") # Output ：Hello World
print("Hello"+"World") # Output ：HelloWorld
print("Hello"+" "+"World") # Output ：Hello World

String processing (8 Common use )

len(): Returns the length of the string , That is, the number of single elements in the string

length=len(target_string) #target-string Is the target string variable 

upper(): Convert all characters in the string to uppercase

lower(): Convert all characters to lowercase

title(): Change the first letter of all words in the string to uppercase , The other letters are still lowercase

new_string="Tom is good"
print(name_string.upper()) # Output ：TOM IS GOOD
print(name_string.lower()) # Output ：tom is good
print(name_string.title()) # Output ：Tom Is Good

strip(): You can remove both sides of the string （ Does not include internal ） All spaces . Using this method , You can also specify parameters , Remove specific characters specified on both sides

split(): Implement string splitting . This method is based on the provided delimiter , Split a string into a list of characters , If no delimiter is provided , The program will default to the space （ Tabulation 、 Line break, etc ） As a separator .

find(): Using this method, you can find substrings in a long string . If in this string , There are one or more substrings , The method returns the leftmost index of the first substring , If no qualified substring is found , Then return to -1.

replace(): To replace substrings in a given string .

source_string.replace(old_string, new_string)