Python String replace() Method | Tutorial Reference

How to use Python's replace() method to replace substrings in strings, including controlling replacements with the optional count parameter.

The String replace() method returns a copy of the string in which all occurrences of a specified substring are replaced with another substring.

Syntax

my_string.replace(old, new, count)

replace() Parameters

Python String replace() method parameters:

Parameter	Condition	Description
`old`	Required	A string you want to replace
`new`	Required	A string you want to replace old string with
`count`	Optional	An integer specifying number of replacements to perform. Default behaviour is replace all occurrences

replace() Return Value

Python String replace() method returns a copy of the string where the old substring is replaced with the new string. The original string remains unchanged.

If the old substring is not found, it returns a copy of the original string.

Examples

Example 1: Replace Substrings in a String with replace()

The replace() method replaces a substring within a string.

my_str = 'Tom is here!'
result = my_str.replace('Tom','David')
print(result) # Output: David is here!

output

David is here!

Example 2: Replace All Substrings in a String with replace()

By default, if you don't specify the count parameter, the replace() method replaces all occurrences of the specified substring.

my_str = 'Long, Longer, Longest'
result = my_str.replace('Long','Small')
print(result) # Output: Small, Smaller, Smallest

output

Small, Smaller, Smallest

Example 3: Replace a certain number of Substrings in a String with replace()

If you specify the optional parameter count, then only the first count occurrences are replaced.

my_str = 'Long, Longer, Longest'
result = my_str.replace('Long','Small', 2)
print(result) # Output: Small, Smaller, Longest

output

Small, Smaller, Longest