Rule: methods that change, add, or delete characters do not alter the string to which they are applied; they return a new string that is a copy of the old string, suitably modified
String methods: type of characters in string (return True or False) [strtype.py]
S.isalpha() — True if only alphabetics (letters) in S
S.isalnum() — True if only alphanumerics (letters or digits) in S
S.isdigit() — True if only digits in S
S.isspace() — True if only white space (blanks, tabs, newlines) in S
S.isupper() — True if all letters in S are upper case
S.islower() — True if all letters in s are lower case
String methods: changing case of letters in string (return result of applying method) [strchcase.py]
S.capitalize() — If the first character of S is a letter, capitalize it
S.title() — Capitalize each word in S
S.lower() — Change all upper case letters in S to lower case
S.upper() — Change all lower case letters in S to upper case
S.swapcase() — Change all upper case letters in S to lower case and vice versa
String methods: stripping blanks from strings (return result of applying method) [strstrip.py]
S.lstrip() — Delete all leading white spaces from S
S.rstrip() — Delete all trailing white spaces from S
S.strip() — Delete all leading and trailing white spaces from S
String methods: find characters and substrings (return position or cause exception) [strfind.py]
S.find(s) — Return the index of the first occurrence of s in S; −1 if s not in S
S.index(s) — Return the index of the first occurrence of s in S; ValueError exception if s not in S
S.rfind(s) — Return the index of the last occurrence of s in S; −1 if s not in S
S.rindex(s) — Return the index of the last occurrence of s in S; ValueError exception if s not in S