pythonstring

Changing a character in a string

What is the easiest way in Python to replace a character in a string?

For example:

text = "abcdefg";
text[1] = "Z";
           ^
Solution

  • Don't modify strings.

    Work with them as lists; turn them into strings only when needed.

    >>> s = list("Hello zorld")
>>> s
['H', 'e', 'l', 'l', 'o', ' ', 'z', 'o', 'r', 'l', 'd']
>>> s[6] = 'W'
>>> s
['H', 'e', 'l', 'l', 'o', ' ', 'W', 'o', 'r', 'l', 'd']
>>> "".join(s)
'Hello World'

    Python strings are immutable (i.e. they can't be modified). There are a lot of reasons for this. Use lists until you have no choice, only then turn them into strings.