Python String partition() Method

In Python, the partition() method is a handy tool when we need to split a string into exactly three parts based on the first occurrence of a given separator.

It returns a tuple containing:

1. The part before the separator
2. The separator itself
3. The part after the separator

This is especially useful when we're parsing strings like filenames, email addresses, key-value pairs, or structured messages where we're expecting a predictable format with a known delimiter.

Let's understand with the help of an example:

s = "Geeks for Geeks"

res = s.partition("for")
print(res)

('Geeks ', 'for', ' Geeks')

Explanation: partition("for") splits the string s at the first occurrence of "for". It returns a tuple with three parts:

• Part before the separator: 'Geeks '
• The separator itself: 'for'
• Part after the separator: ' Geeks'

Hence the output: ('Geeks ', 'for', ' Geeks')

Syntax

string.partition(separator)

Parameters: 

• separator(required): a substring that separates the string

Return Type:

• Returns a tuple of three strings: (before_separator, separator, after_separator).
• If the separator is not found, the tuple returned is (string, '', '').

Examples of partition() Method

Example 1: Using partition() with a valid separator

This example demonstrates the behavior when the separator exists in the string:

s = "Python is fun"

res = s.partition("is")
print(res) 

('Python ', 'is', ' fun')

Explanation:

• string is split at the first occurrence of the separator "is".
• the method returns a tuple containing the three parts of the string.

Example 2: When the separator is not found

If the separator is absent, the partition() method returns a specific result.

s = "Python is fun"

res = s.partition("Java")
print(res)  

('Python is fun', '', '')

Explanation:

• Since the separator "Java" is not present in the string, the entire string is returned as the first element of the tuple.
• The second and third elements are empty strings.

Example 3: Working with multiple occurrences of the separator

partition() method only considers the first occurrence of the separator:

s = "Learn Python with GeeksforGeeks"

res = s.partition("Python")
print(res) 

('Learn ', 'Python', ' with GeeksforGeeks')

Explanation:

• string is split at the first occurrence of "Python".
• subsequent occurrences of the separator are ignored by the partition() method.

Example 4: Using special characters as the separator

partition() method works seamlessly with special characters:

s = "key:value"

res = s.partition(":")
print(res)  

('key', ':', 'value')

Explanation:

• string is split into three parts at the occurrence of ":".
• this method is particularly useful when parsing key-value pairs in a structured format.

Also read: tuple, strings, delimeter.