how does python do string matching code example

Example: approximate string matching python

#Installation
pip install fuzzywuzzy

#import
from fuzzywuzzy import fuzz

# Compare whole 2 strings
fuzz.ratio("Catherine M Gitau","Catherine Gitau")
#91

# Compares only untill the length of smallest string,
# In below case strings that will be compared are, "Catherine M. Gi" & "Catherine Gitau" 
fuzz.partial_ratio("Catherine M. Gitau","Catherine Gitau")
#100