Python string replace() method with example

The replace() method in Python is a built-in string method used to replace all occurrences of a specified substring within a string with another substring. It returns a new string with the replacements made.


string.replace(old, new, count)

old: This parameter specifies the substring that you want to replace. All occurrences of this substring within the string will be replaced.

new: This parameter specifies the substring that will replace the occurrences of the old substring.

count (optional): This parameter determines the number of occurrences to be replaced. If count is not specified, all occurrences of the old substring will be replaced.

How to use the replace() method:

string = "Hello, World!"
new_string = string.replace("Hello", "Hi")

print(new_string) # Output: Hi, World!

Example 1

Replacing multiple substrings.

string = "The quick brown fox jumps over the lazy dog."
replaced_string = string.replace("quick", "fast").replace("brown", "red").replace("lazy", "active")

print(replaced_string) # Output: The fast red fox jumps over the active dog.

Example 2

Case-insensitive replacement.

string = "The cat chased the CAT."
new_string = string.replace("cat", "dog", 1)

print(new_string) # Output: The dog chased the CAT.

Example 3

Replace specific time and event-related substrings in a string.

string = "Let's meet at 9:30 PM for dinner."
replacements = {
  "9:30": "7:00",
  "PM": "AM",
  "dinner": "breakfast"

for old, new in replacements.items():
  string = string.replace(old, new)

print(string) # Output: Let's meet at 7:00 AM for breakfast.