General Form of replacement of Python strings

In computer languages, Python strings are commonly used. In actual application, if you are confused about Python strings, the following is a detailed description of the application process.

Alignment of Python strings in output:

 
 

  
  
S.ljust(width,[fillchar])   
 
 

# The output width is a string of characters, and the S is left aligned. The missing part is filled with fillchar. The default value is space.

 
 

  
  
S.rjust(width,[fillchar]) #  
 
 

Right alignment

 
 

  
  
S.center(width, [fillchar]) #  
 
 

In the center alignment S. zfill (width) # convert S to width length, and align it on the right. The missing part uses 0 to supplement the search and replacement in the string:

 
 

  
  
S.find(substr, [start, [end]])   
 
 

# Return the number of the first letter of substr in S. If S does not contain substr,-1 is returned. The functions of start and end are equivalent to searching in S [start: end ].

 
 

  
  
S.index(substr, [start, [end]])   
 
 

# It is the same as find (), but a runtime error is returned when S does not contain substr.

 
 

  
  
S.rfind(substr, [start, [end]])   
 
 

# Return the number of the first letter of the last occurrence of substr in S. If there is no substr in S,-1 is returned, that is, the first letter of the first occurrence of substr from the right.

 
 

  
  
S.rindex(substr, [start, [end]])   
  
  
S.count(substr, [start, [end]]) #  
 
 

Calculates the number of times that substr appears in S.

 
 

  
  
S.replace(oldstr, newstr, [count])   
 
 

# Replace oldstar with newstr in S, and count with the number of replicas. This is a common form of replacement, and some functions Replace special characters.