callee provides a wide collection of argument matchers to use with the standard unittest.mock library.

It allows you to write simple, readable, and powerful assertions on how the tested code should interact with your mocks:

from callee import Dict, StartsWith, String

    String() & StartsWith('https://'),
    params=Dict(String(), String()))

With callee, you can avoid both the overly lenient mock.ANY, as well as the tedious, error-prone code that manually checks Mock.call_args and call_args_list.

User’s Guide

Start here for the installation instructions and a quick, complete overview of callee and its usage.