String Methods

This is a list of common string methods. In it, S is the string to which the method is applied, and s and ta are other strings.

OperationDescription
S.capitalize()If the first character of S is a letter, capitalize it
S.count(s)Count the number of times s occurs in S
S.endswith(s)True if S ends with s; False otherwise
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.isalnum()True if S contains only alphanumerics (letters and digits); False otherwise
S.isalpha()True if S contains only alphabetics (letters); False otherwise
S.isdigit()True if S contains only digits; False otherwise
S.islower()True if all letters in S are lower case; False otherwise
S.isspace()True if S contains only white space; False otherwise
S.isupper()True if all letters in S are upper case; False otherwise
S.lower()Change all upper case letters in S to lower case
S.lstrip()Delete all leading white space from S and return the result
S.replace(s,t)Replace all occurrences of s with t 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
S.rstrip()Delete all trailing white space from S
S.strip()Delete all leading and trailing white space from S
S.swapcase()Change all upper case letters in S to lower case and all lower case letters to upper case
S.title()Capitalize each word in S
S.upper()Change all lower case letters in S to upper case

List Methods

This is a list of list methods. In it, L is the list to which the method is applied, M is a list, x is an element to be added to, looked for, or removed from, a list, and i is an index of a list element.

OperationDescription
L.append(x)Append element x to L
L.count(x)Count the number of times x occurs in L
L.extend(M)Extend L by adding the elements of M at the end
L.index(x)Return the index of the first occurrence of x in L; ValueError exception if x not in L
L.insert(i,x)Insert x at position i in L
L.pop()Remove and return the last element of L
L.pop(i)Remove and return the element of L at position i; IndexError exception if i out of range
L.remove(x)Remove the first occurrence of x from L; ValueError exception if x not in L
L.reverse() Reverse L in place (does not make a copy)
L.sort()Sort L in place (does not make a copy)

Matt Bishop
Department of Computer Science
University of California at Davis
Davis, CA 95616-8562 USA
Last modified: Version of January 28, 2019 at 8:21PM
Winter Quarter 2019
You can get a PDF version of this