Python String Methods

Python string methods is a collection of in-built Python functions that operates on lists.

Note: Every string method in Python does not change the original string instead returns a new string with the changed attributes. 

Python string is a sequence of Unicode characters that is enclosed in quotation marks. In this article, we will discuss the in-built string functions i.e. the functions provided by Python to operate on strings.

Case Changing of Python String Methods

The below Python functions are used to change the case of the strings. Let’s look at some Python string methods with examples:

• lower(): Converts all uppercase characters in a string into lowercase
• upper(): Converts all lowercase characters in a string into uppercase
• title(): Convert string to title case
• swapcase(): Swap the cases of all characters in a string
• capitalize(): Convert the first character of a string to uppercase

Example: Changing the case of Python String Methods

# Python3 program to show the
# working of upper() function
text = 'geeKs For geEkS'

# upper() function to convert
# string to upper case
print("\nConverted String:")
print(text.upper())

# lower() function to convert
# string to lower case
print("\nConverted String:")
print(text.lower())

# converts the first character to 
# upper case and rest to lower case 
print("\nConverted String:")
print(text.title())

# swaps the case of all characters in the string
# upper case character to lowercase and viceversa
print("\nConverted String:")
print(text.swapcase())

# convert the first character of a string to uppercase
print("\nConverted String:")
print(text.capitalize())

# original string never changes
print("\nOriginal String")
print(text)

Converted String:
GEEKS FOR GEEKS

Converted String:
geeks for geeks

Converted String:
Geeks For Geeks

Converted String:
GEEkS fOR GEeKs

Original String
geeKs For geEkS

Time complexity: O(n) where n is the length of the string ‘text’
Auxiliary space: O(1)

List of String Methods in Python

Here is the list of in-built Python string methods, that you can use to perform actions on string:

Note: For more information about Python Strings, refer to Python String Tutorial.

Python String Methods – FAQs

What Are the Common String Methods in Python?

Python provides a variety of string methods for manipulating and working with strings. Some of the most common string methods include:

• upper(): Converts all characters in a string to uppercase.
• lower(): Converts all characters in a string to lowercase.
• find(substring): Returns the lowest index in the string where the substring is found.
• strip(): Removes any leading and trailing characters (space is the default).
• replace(old, new): Replaces occurrences of a substring within the string.
• split(delimiter): Splits the string at the specified delimiter and returns a list of substrings.
• join(iterable): Concatenates elements of an iterable with a specified separator.
• startswith(prefix): Checks if the string starts with the specified prefix.
• endswith(suffix): Checks if the string ends with the specified suffix.

How to Find a Substring in Python?

To find a substring in a string, you can use the find() method. It returns the lowest index of the substring if it is found. If the substring is not found, it returns -1.

Example:

text = "Hello, World!"
index = text.find("World")
print(index)  # Output: 7

# If the substring is not found
index = text.find("Python")
print(index)  # Output: -1

How to Convert a String to Lower Case in Python?

You can convert all characters in a string to lowercase using the lower() method.

Example:

text = "Hello, World!"
lowercase_text = text.lower()
print(lowercase_text)  # Output: hello, world!

What is the strip() Method Used for in Python?

The strip() method is used to remove leading and trailing characters from a string. By default, it removes whitespace, but you can specify a different character or set of characters to remove.

Example:

text = "   Hello, World!   "
stripped_text = text.strip()
print(stripped_text)  # Output: "Hello, World!"

# Removing specific characters
text = "###Hello, World!###"
stripped_text = text.strip("#")
print(stripped_text)  # Output: "Hello, World!"

How to Replace Characters in a String in Python?

To replace characters or substrings in a string, you can use the replace() method. It replaces all occurrences of the specified substring with another substring.

Example:

text = "Hello, World!"
replaced_text = text.replace("World", "Python")
print(replaced_text)  # Output: Hello, Python!

# Replacing characters
text = "banana"
replaced_text = text.replace("a", "o")
print(replaced_text)  # Output: bonono

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