2 Effective methods for Python string substitution

Python string substitution can be implemented in 2 ways:
1 is the method of using the string itself.
2 replacing a string with a regular

Here's an example to experiment with:
A = ' Hello word '
I replaced word in a string with Python
1 Replace method with the string itself
A.replace (' word ', ' python ')
The result of the output is Hello Python

2 use regular expressions to complete the substitution:
Import re
Strinfo = Re.compile (' word ')
b = strinfo.sub (' python ', a)
Print B
The result of the output is also Hello Python

2 Effective methods for Python string substitution