Python Text Processing - Word Replacement

Replacing the complete string or a part of string is a very frequent requirement in text processing. The replace() method returns a copy of the string in which the occurrences of old have been replaced with new, optionally restricting the number of replacements to max.

Following is the syntax for replace() method

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

Parameters

• old This is old substring to be replaced.

• new This is new substring, which would replace old substring.

• max If this optional argument max is given, only the first count occurrences are replaced.

This method returns a copy of the string with all occurrences of substring old replaced by new. If the optional argument max is given, only the first count occurrences are replaced.

Example

Example - Usage of replace() method

The following example shows the usage of replace() method.

main.py

str = "this is string example....wow!!! this is really string"
print(str.replace("is", "was"))
print(str.replace("is", "was", 3))

Result

When we run above program, it produces the following result

thwas was string example....wow!!! thwas was really string
thwas was string example....wow!!! thwas is really string

Example - Replacement Ignoring Case

main.py

import re
sourceline  = re.compile("Tutor", re.IGNORECASE)
 
Replacedline  = sourceline.sub("Tutor","Tutorialspoint has the best tutorials for learning.")
print (Replacedline)

Output

When we run the above program, we get the following output

Tutorialspoint has the best Tutorials for learning.