In pytest returns magicMock instance instead of return value - unit-testing

Question

i have a sample method and a pytest method for it.
import pytest
from datetime import datetime
# this is the method to test
def get_time_of_day():
"""return string Night/Morning/Afternoon/Evening depending on the hours range"""
time = datetime.now()
print(time.hour)
if 0 <= time.hour <6:
return "Night"
if 6 <= time.hour < 12:
return "Morning"
if 12 <= time.hour <18:
return "Afternoon"
return "Evening"
#pytest method, where I am trying to mock datetime.now
def test_get_time_of_day(mocker):
mock_now = mocker.patch("tests.test_sample.datetime")
mock_now.now.return_value = datetime(2016, 5, 20, 14, 10, 0)
assert get_time_of_day() == "Afternoon"
But when I try to run the pytest as follow
python3 -m pytest test_sample.py
I get TypeError: '<=' not supported between instances of 'int' and 'MagicMock'
I have a directory tests inside that I have the python file test_sample.py. In this file, I have written this code.
I have referred this page:
So do anyone Know to solve this issue. Thank you

Answer 1

This is because when you are assigning a value to mock_now.now.return_value, datetime is already patched and returns a MagicMock instead of the datetime object as you expect.
This would work:
def test_get_time_of_day(mocker):
dt = datetime(2016, 5, 20, 14, 10, 0)
mock_now = mocker.patch("tests.test_sample.datetime")
mock_now.now.return_value = dt
assert get_time_of_day() == "Afternoon"
As you would typically patch objects in modules that you test (instead of within the test module itself), you would not run into this issue.