Python String replace() Function

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

note

By default, all occurrences of the substring are replaced. However, you can limit the number of replacements by specifying optional parameter count.

Syntax

my_string.replace(old, new, count)

replace() Parameters

Python String replace() function 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() function 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