String: is a finite sequence of 0 or more characters
The string formatting type is as follows
Terminal or pycharm view string format type command: x.tab ()====x is the assigned variable name
x.capitalize()----capitalize the first letter
The execution result is as shown in the figure below
x.casefold()----all changed to lowercase
The execution result is as shown in the figure below
x.center()-----center filling
The execution result is as shown in the figure below
x.expandtabs()----tab function of string link
Execute as shown below
x.ljust()-----The string is filled from left to right
Execute as shown below
x.rjust()-----string fills from right to left
Execute as shown below
x.swapcase()---case swap
Execute as shown below
x.title()---Convert to title, the first letter of each word is capitalized
Execute as shown below
x.upper()-----Change all lowercase to uppercase
Execute as shown below
x.zfill()-----Specify the length of the string, and fill all the places that are not enough with 0
Execute as shown below
x.strip()-----Dead skin on both sides of the string [such as \n spaces, etc.]
Execute as shown below
x.lstrip()----remove the dead skin on the left
Execute as shown below
x.rstrip()----remove the dead skin on the right
Execute as shown below
x.format()------refer to external variables [there are 2 ways to implement this method]
Execute as shown below
Reference and assignment by parameter position
