Pytest: Mocking slow external API call

We have a module called mymath (again) that does some computation for us. I think it uses the Pythagoras theorem to calculate the distance from the “origin”.

import externalapi

def compute(x, y):
    xx = externalapi.remote_compute(x)
    yy = externalapi.remote_compute(y)
    result = (xx+yy) ** 0.5
    return result

It uses an external API implemented in the externalapi.py file to compue the square of each number. Unfortunatelly this external API is slow.

import time

def remote_compute(x):
    time.sleep(5) # to imitate long running process
    return x*x

We can try to run the following code. It will take 10 seconds to compute this. When testing the mymath library we don’t want to wait 10 seconds for every test-case.

time python use_mymath.py

import mymath

print(mymath.compute(3, 4))