Handle Dynamic function call during pytest

Question

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When main.py is executed, the Python interpreter scans all files and executes any functions that were called at the beginning.

In source/settings.py, there's a function called get_settings(): which act as global variable with function call.

def get_settings():
   # Retrieves settings for production environment
   return {}  # some_dict
    
settings = get_settings()

This function is intended to run in production or other environments.

However, when pytest starts, I want to replace the execution of get_settings() with a different function located in tests/conftest.py:

def get_local_settings():
    # Retrieves settings from the development database
    return {}  # some_dict

with patch('source.settings.get_settings') as mock_settings:
    mock_settings.return_value = get_local_settings()

I thought that conftest.py will be called in beginning of test and with mock_settings.return_value will be assigned. So, whenever get_settings() is called get_local_settings() value will be returned. Despite implementing this logic, get_settings() continues to be called when pytest starts.

I'm seeking a solution that doesn't involve modifying source/settings.py with conditional logic like:

if ENV == LOCAL:
    settings = tests.conftest.get_local_settings()
else:
    settings = get_settings()

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