String Reference Cheat Sheet

In Python, there are a lot of things you can do with strings. In this cheat sheet, you’ll find the most common string operations and string methods.

String operations

  • len(string) Returns the length of the string
  • for character in string Iterates over each character in the string
  • if substring in string Checks whether the substring is part of the string
  • string[i] Accesses the character at index i of the string, starting at zero
  • string[i:j] Accesses the substring starting at index i, ending at index j-1. If i is omitted, it's 0 by default. If j is omitted, it's len(string) by default.

String methods

  • string.lower() / string.upper() Returns a copy of the string with all lower / upper case characters
  • string.lstrip() / string.rstrip() / string.strip() Returns a copy of the string without left / right / left or right whitespace
  • string.count(substring) Returns the number of times substring is present in the string
  • string.isnumeric() Returns True if there are only numeric characters in the string. If not, returns False.
  • string.isalpha() Returns True if there are only alphabetic characters in the string. If not, returns False.
  • string.split() / string.split(delimiter) Returns a list of substrings that were separated by whitespace / delimiter
  • string.replace(old, new) Returns a new string where all occurrences of old have been replaced by new.
  • delimiter.join(list of strings) Returns a new string with all the strings joined by the delimiter

https://docs.python.org/3/library/stdtypes.html#string-methods

 

Built-in Types — Python 3.8.1 documentation

The following sections describe the standard types that are built into the interpreter. The principal built-in types are numerics, sequences, mappings, classes, instances and exceptions. Some collection classes are mutable. The methods that add, subtract,

docs.python.org