Python - replace first character in string

In this article, we would like to show you how to replace first character in string in Python.

Quick solution:

text = "ABC ABC ABC"
replacement = "X"
result = text.replace(text[0:1], replacement, 1)

print(result)  # XBC ABC ABC

Practical example using replace() method

In this example, we use replace() method to replace first character in the text string.

We use the following syntax:

replace(old, new, count)

Where:

• old - is a substring to replace,
• new - is the replacement,
• count (optional argument) - is the number of times we want to replace the specified substring. You need to set it to 1, so you won't replace anything but the first occurrence of the substring.

Practical example:

text = "ABC ABC ABC"
replacement = "X"
result = text.replace(text[0:1], replacement, 1)

print("Before: ", text)    # ABC ABC ABC
print("After:  ", result)  # XBC ABC ABC

Output:

Before:  ABC ABC ABC
After:   XBC ABC ABC

Note:

If you don't set the count argument, by default the replace() method will replace all occurrences of the A letter (substring).

Output:

Before:  ABC ABC ABC
After:   XYC XBC XBC

References

• Python 3.x documentation - String replace() method