String Methods in Python

In Python, you can manage strings using various methods. There are quite a few of them.

Why are methods useful? Often, a method can achieve the same result as multiple instructions. Therefore, using methods can reduce the length of your source code and improve its readability.

What are the string methods in Python?

Here's a complete list of all the methods applicable to strings.

capitalize

Returns the string with the first character capitalized and the rest in lowercase.

string_name.capitalize()

Example

name="Andrea MININI"
name.capitalize()

Output

'Andrea minini'

center

Centers the string within a specified width, padding it with spaces on both sides. The second parameter (optional) specifies a fill character instead of spaces.

string_name.center(width [, 'fillchar'])

Example

name="Andrea Minini"
name.center(20, '-')

Output

'---Andrea Minini----'

count

Counts the number of occurrences of a substring within the string. Optional parameters specify the start and end positions for the search.

string_name.count('sub' [, start [, end]])

Example

name="Andrea Minini"
name.count('ni')

Output

2

decode

Decodes the string using the specified codec. If not specified, it uses the default string codec. The error parameter handles exceptions for encoding errors.

string_name.decode([encoding [, error]])

encode

Encodes the string using the specified codec. If not specified, it uses the default string codec. The error parameter handles exceptions for encoding errors.

string_name.encode([encoding [, error]])

endswith

Returns true if the string ends with the specified suffix; otherwise, it returns false. Optional parameters define the start and end positions for the search.

string_name.endswith(suffix [, start [, end]])

Example

name="Andrea Minini"
name.endswith('ni', 1, 5)

Output

False

expandtabs

Replaces tabs in the string with a specified number of spaces. If the tab size parameter is not specified, it defaults to 8 spaces.

string_name.expandtabs(tabsize)

Example

name="Andrea \t Minini"
name.expandtabs(1)

Output

Andrea Minini

find

Searches for a substring within the string. Returns the position of the first occurrence from the left. Returns -1 if not found. Optional parameters define the start and end positions for the search.

string_name.find(sub [, start [, end]])

Example

name="Andrea Minini"
name.find('ni')

Output

9

index

Similar to find, but raises a ValueError if the substring is not found. Optional parameters define the start and end positions for the search.

string_name.index(sub [, start [, end]])

Example

name="Andrea Minini"
name.index('ni')

Output

9

isalnum

Returns true if the string is alphanumeric.

string_name.isalnum()

Example

name="Andrea Minini"
name.isalnum()

Output

false

isalpha

Returns true if the string is alphabetic. Otherwise, it returns false.

string_name.isalpha()

Example

name="Andrea Minini"
name.isalpha()

Output

false

It returns false because the string "Andrea Minini" contains a space (a non-alphabetic character).

isdecimal

Returns true if the string contains only decimal digits ("0123456789"). Otherwise, it returns false.

string_name.isdecimal()

Example

score="30"
score.isdecimal()

Output

true

If the variable has a numeric value (e.g., score=30), the method raises an exception because it's not a string.

isdigit

Returns true if the string contains only digits, including subscript and superscript. Otherwise, it returns false.

string_name.isdigit()

Example

score="30²"
score.isdigit()
score.isdecimal()

Output

true
false

Unlike isdecimal, the isdigit method includes more numeric symbols (subscript and superscript).

isnumeric

Returns true if the string contains only numeric characters, including decimal digits, subscript, superscript, fraction symbols, Roman numerals, etc. Otherwise, it returns false.

string_name.isnumeric()

Example

score="30¼"
score.isnumeric()
score.isdigit()
score.isdecimal()

Output

true
false
false

Unlike isdigit, the isnumeric method includes more numeric symbols (e.g., fractions).

islower

Returns true if the string contains only lowercase letters. Otherwise, it returns false.

string_name.islower()

Example

name="Andrea Minini"
name.islower()

Output

false

The method returns false because the string contains two uppercase letters (A and M).

isspace

Returns true if the string contains only spaces. Otherwise, it returns false.

string_name.isspace()

Example

name="Andrea Minini"
name.isspace()

Output

false

The method returns false because the string contains other characters besides spaces.

istitle

Returns true if the string is titlecased (each word starts with an uppercase letter followed by lowercase letters).

string_name.istitle()

Example

name="Andrea Minini"
name.istitle()

Output

true

isupper

Returns true if the string contains only uppercase letters. Otherwise, it returns false.

string_name.isupper()

Example

name="ANDREA MININI"
name.isupper()

Output

true

join

Joins a list of strings into a single string, separated by a specified character or string.

'separator'.join(seq)

Example

'-'.join(['a', 'b', 'c'])

Output

a-b-c

list

Converts a string into a list of its characters.

list(string_name)

Example

string="abc"
list(string)

Output

['a', 'b', 'c']

ljust

Left-justifies a string, padding it with spaces on the right. If the specified width is less than the string length, it returns the original string. The optional second parameter specifies a fill character.

string_name.ljust(width [, fillchar])

Example

name="Andrea Minini"
name.ljust(20, '-')

Output

'Andrea Minini-------'

lower

Converts all characters in the string to lowercase.

string_name.lower()

Example

name="Andrea Minini"
name.lower()

Output

'andrea minini'

lstrip

Removes leading spaces from a string. If a character is specified, it removes that character from the start of the string.

string_name.lstrip(char)

Example

name="Andrea Minini"
name.lstrip('A')

Output

'ndrea Minini'

replace

Replaces a substring with another substring within the string. The optional count parameter specifies the start position for the search.

string_name.replace(old, new[, count])

Example

name="Andrea Minini"
name.replace('Minini', 'Rossi')

Output

'Andrea Rossi'

rfind

Searches for a substring from the right. Returns the position of the first occurrence from the right. Returns -1 if not found. Optional parameters define the start and end positions for the search.

string_name.rfind(sub [, start [, end]])

Example

name="Andrea Minini"
name.rfind('ni')
name.find('ni')

Output

11
9

The rfind method finds the last occurrence, while the find method finds the first.

rindex

Similar to rfind but raises a ValueError if the substring is not found. Optional parameters define the start and end positions for the search.

string_name.rindex(sub [, start [, end]])

Example

name="Andrea Minini"
name.rindex('ni')
name.index('ni')

Output

11
9

rjust

Right-justifies a string, padding it with spaces on the left. If the specified width is less than the string length, it returns the original string. The optional second parameter specifies a fill character.

string_name.rjust(width [, fillchar])

Example

name="Andrea Minini"
name.rjust(20, '-')

Output

'-------Andrea Minini'

rsplit

Splits a string into a list of elements using the specified separator. If no separator is specified, the method defaults to space, splitting the string into words. The optional maxsplit parameter limits the number of elements from the right.

string_name.rsplit([sep [, maxsplit]])

Example

name="Andrea Minini"
name.rsplit("n", 1)
name.split("n", 1)

Output

['Andrea Mini', 'i']
['A', 'drea Minini']

What is the difference between split and rsplit?

If the maxsplit parameter is not specified, split and rsplit give the same result. Otherwise, split breaks the string from the left (e.g., ['A', 'drea Minini']) while rsplit breaks it from the right (e.g., ['Andrea Mini', 'i']).

rstrip

Removes a specified substring or character from the end of the string (right strip). If no character is specified, the method defaults to space.

string_name.rstrip([chars])

Example

name="Andrea Minini"
name.rstrip("ni")

Output

'Andrea M'

split

Splits the string into a list of elements using the specified separator. If no separator is specified, the method defaults to space, splitting the string into words. The optional maxsplit parameter limits the number of elements from the left.

string_name.split([sep [, maxsplit]])

 

Example

name="Andrea Minini"
name.split("n")

Output

['A', 'drea Mi', 'i', 'i']

splitlines

Splits the string into a list of elements at line breaks. Each list element is a line of text. The line break character \n is not included unless the optional keepends parameter is specified.

string_name.splitlines([keepends])

 

Example

name="Andrea Minini \n second line"
name.splitlines()
name.splitlines(1)

Output

['Andrea Minini ', ' second line']
['Andrea Minini \n', ' second line']

startswith

Returns true if the string starts with the specified prefix. Optional parameters define the start and end positions for the check.

string_name.startswith(prefix [, start [, end]])

Example

name="Andrea Minini"
name.startswith("And")
name.startswith("And", 4, 8)

Output

true
false

strip

Removes the specified character or substring from the beginning and end of a string. If the character is not specified, the method defaults to removing spaces.

string_name.strip([chars])

Example

name="--Andrea Minini--"
name.strip("-")

Output

Andrea Minini

swapcase

Swaps the case of all characters in the string, converting uppercase to lowercase and vice versa.

string_name.swapcase()

Example

name="Andrea Minini"
name.swapcase()

Output

'aNDREA mININI'

title

Returns the string with each word's first letter capitalized and the remaining letters in lowercase.

string_name.title()

Example

name="andrea minini"
name.title()

Output

'Andrea Minini'

translate

Returns the string with characters mapped through a translation table. The specified characters are removed.

string_name.translate(table[, deletechars])

upper

Converts all characters in the string to uppercase.

string_name.upper()

Example

name="Andrea Minini"
name.upper()

Output

'ANDREA MININI'

zfill

Pads the string on the left with zeros to reach a specified width. If the string is longer than the specified width, it returns the original string.

string_name.zfill(width)

Example

name="Andrea Minini"
name.zfill(20)

Output

'0000000Andrea Minini'