Trouble mocking the return value of python-gitlab method

I am trying to mock the return value of the following method

import gitlab
from unittest.mock import patch

def get_all_iters():
   gl = gitlab.Gitlab(url='test_url', private_token)
   result = gl.groups.get(1).iterations.list() # trying to mock the result of this method call

   return result

@patch('gitlab.Gitlab')
@patch('gitlab.v4.objects.GroupManager')
@patch('gitlab.mixins.ListMixin.list')
def test_my_code(mockGitlab, mockGroup, mockList):
   mockList.return_value = ['a', 'b']
   result = get_all_iters()
   print(result)

Although I have tried to mock the return value of the method call, it is still returning the mock object instead of what I tried to mock

<MagicMock name='Gitlab().groups.get().iterations.list()' id='1688988996464'>

Below I'll show you a solution for your problem:

import gitlab
from unittest.mock import patch

def get_all_iters():
   #gl = gitlab.Gitlab(url='test_url', private_token) # <--- Remove your instruction and substitute with the following
   gl = gitlab.Gitlab(url='test_url', private_token='test_token_value')  # <--- HERE I have set the value for the argument private_token
   result = gl.groups.get(1).iterations.list() # trying to mock the result of this method call
   return result

# I leave only one patch() as decorator, while other mocks are managed 
# by context managers inserted into the body of the test method
@patch('gitlab.Gitlab')
def test_my_code(mockGitlab):
    instance_gl = mockGitlab.return_value
    with patch.object(instance_gl, 'groups') as mock_groups:
        with patch.object(mock_groups, 'get') as mock_get:
            instance_get = mock_get.return_value
            with patch.object(instance_get, 'iterations') as mock_iterations:
                with patch.object(mock_iterations, 'list') as mockList:
                    # -------> FINALLY here are your test instructions
                    mockList.return_value = ['a', 'b']
                    result = get_all_iters()
                    print(result)

test_my_code()

The execution of the test method on my system is:

['a', 'b']

that is the print of the desired value for result set by your instruction mockList.return_value = ['a', 'b'].

Why are there so many mocks object?

Note the instructions:

instance_gl = mockGitlab.return_value
instance_get = mock_get.return_value

By those instructions we can get the right Mock objects.

Furthermore note the presence of the instructions patch.object() and not only of the patch() instruction.

There is probably a simpler solution, but since you desire to mock the list get by the complex instruction:

gl.groups.get(1).iterations.list()

I have been able to find only this way!

This post is old but useful to add more details to my explanation.