Python String replace()

Python String replace()

The replace() method returns a copy of the string where all occurrences of a substring is replaced with another substring.

The syntax of replace() is:

str.replace(old, new [, count]) 

replace() parameters

The replace() method can take maximum of 3 parameters:

  • old - old substring you want to replace
  • new - new substring which will replace the old substring
  • count (optional) - the number of times you want to replace the old substring with the new substring

Note: If count is not specified, the replace() method replaces all occurrences of the old substring with the new substring.


Return Value from replace()

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

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


Example 1: Using replace()

song = 'cold, cold heart'

# replacing 'cold' with 'hurt'
print(song.replace('cold', 'hurt'))

song = 'Let it be, let it be, let it be, let it be'

# replacing only two occurences of 'let'
print(song.replace('let', "don't let", 2))

Output

hurt, hurt heart
Let it be, don't let it be, don't let it be, let it be

More Examples on String replace()

song = 'cold, cold heart'
replaced_song = song.replace('o', 'e')

# The original string is unchanged
print('Original string:', song)

print('Replaced string:', replaced_song)

song = 'let it be, let it be, let it be'

# maximum of 0 substring is replaced
# returns copy of the original string
print(song.replace('let', 'so', 0))

Output

Original string: cold, cold heart
Replaced string: celd, celd heart
let it be, let it be, let it be