Mock a single function boto3 / moto

test.py

# Useful for filling in unimplemented moto https://github.com/spulec/moto functions for instance

import botocore.client
original_api_call = botocore.client.BaseClient._make_api_call
def mock_api_call(self, operation_name, api_params):
    if operation_name == 'ListAliases':
        return {
            "Aliases": []
        }

    return original_api_call(self, operation_name, api_params)
    
# ...

class TestCase(unittest.TestCase):
    # ...
    @patch('botocore.client.BaseClient._make_api_call', new=mock_api_call)
    def test_function(self):
        # ...