In the source code you can find a simple explanation of what does partial ratio in fuzzywuzzy does:

Return the ratio of the most similar substring as a number between 0 and 100

In this code snippet you can find the differences

from fuzzywuzzy import fuzz

fuzz.ratio("this is a test", "this is a test!")
Out:    97

fuzz.partial_ratio("this is a test", "this is a test!")
Out:    100

[1] https://github.com/seatgeek/fuzzywuzzy [2] https://github.com/seatgeek/fuzzywuzzy/blob/master/fuzzywuzzy/fuzz.py

In the source code you can find a simple explanation of what does partial ratio in fuzzywuzzy does:

Return the ratio of the most similar substring as a number between 0 and 100

In this code snippet you can find the differences

from fuzzywuzzy import fuzz

fuzz.ratio("this is a test", "this is a test!")
Out:    97

fuzz.partial_ratio("this is a test", "this is a test!")
Out:    100

[1] https://github.com/seatgeek/fuzzywuzzy

[2] https://github.com/seatgeek/fuzzywuzzy/blob/master/fuzzywuzzy/fuzz.py