mock_test.py

import requests
import requests_mock
import pprint

pp = pprint.PrettyPrinter(indent=4)

session = requests.Session()
adapter = requests_mock.Adapter()
session.mount('mock', adapter)

adapter.register_uri('GET', 'mock://test.com', text='mocked')

resp_url = session.get('mock://test.com/?foo=bar')
print(adapter.request_history[0].qs)
#> {u'foo': [u'bar']}

params = {'foo': 'bar'}
resp_arg = session.get('mock://test.com', params=params)
print(adapter.request_history[1].qs)
#> {}