How do I import functions and classes into conftest.py? Or how do I import fixtures and classes into conftest.py?

I start off with all the code in conftest.py. This is in example 1. In example 2 I want to move a functions like def test_username_db(): into a separate file called test_function.py. Then I want to import from test_function.py into conftest.py. The problem is I am getting an error. How do I fix this?

example 1

conftest.py

Also I wrote the database class here.

@pytest.fixture
def test_username_db():
    #  assume bob exists 
    user_db = User.query.filter_by(username='Bob').first() 
    assert user_db != 'Bob'     
  

# other fixtures... 

@pytest.fixture() 
def create_db(new_user, test_username_db):

    
    bind_key="testing_app_db"
    # Create the database and the database table
    db.create_all(bind_key)
    
    db.session.add(new_user)
    db.session.commit()
    
    # yield unlike return doesn't stop when called.
  
    yield test_username_db() 
    yield other fixtures

    db.drop_all(bind_key) 

test_fixture.py

test_fixture.py(create_db)
    create_db()

Example 2

Now imagine I want to split up the extra fixtures into functions in a file called test_function.py.

test_function.py

Also I wrote the database class here.

 
def test_username_db():
    #  assume bob exists 
    user_db = User.query.filter_by(username='Bob').first() 
    assert user_db != 'Bob'  

# other fixtures...

conftest.py

from tests.test_function import test_username_db ...

  

@pytest.fixture() 
def create_db(new_user):
    
    bind_key="testing_app_db"
    # Create the database and the database table
    db.create_all(bind_key)
    
    db.session.add(new_user)
    db.session.commit()
    
    # yield unlike return doesn't stop when called.
  
    yield test_username_db() 
    yield # other functions

    db.drop_all(bind_key) 

test_fixture.py

test_fixture.py(create_db)
    create_db()

This seems okay but the problem is when I run the code in example 2 I get an error.

Here is the error

python -m pytest
========================================================================================= test session starts ==========================================================================================
platform win32 -- Python 3.10.8, pytest-7.1.2, pluggy-1.0.0
rootdir: C:\Users\user\OneDrive\Desktop\flaskcodeusethis\flaskblog2
collected 0 items / 1 error
 
================================================================================================ ERRORS ================================================================================================ 
____________________________________________________________________________________ ERROR collecting test session _____________________________________________________________________________________ 
..\..\..\..\Anaconda3\envs\py\lib\importlib\__init__.py:126: in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
<frozen importlib._bootstrap>:1050: in _gcd_import
    ???
<frozen importlib._bootstrap>:1027: in _find_and_load
    ???
<frozen importlib._bootstrap>:1006: in _find_and_load_unlocked
    ???
<frozen importlib._bootstrap>:688: in _load_unlocked
    ???
..\..\..\..\Anaconda3\envs\py\lib\site-packages\_pytest\assertion\rewrite.py:168: in exec_module
    exec(co, module.__dict__)
app\tests\conftest.py:13: in <module>
    from tests.test_password_function import app, db, UserTest, email_token_and_registration_confirmation_email
E   ModuleNotFoundError: No module named 'tests'
======================================================================================= short test summary info ========================================================================================
ERROR  - ModuleNotFoundError: No module named 'tests'
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

My testing folder looks like this tests folder and files .
Why is this error occurring?

Also the error I posted I am using the function def email_token_and_registration_confirmation_email(): instead of def test_username_db(): .

Also the error I posted I am using the file test_functions_use_db.py instead of test_function.py.

Here is what I tried.

I tried changing the functions test_functions_use_db.py to functions_use_db.py. I get the same effect.

I also found this link https://stackoverflow.com/questions/73191533/using-conftest-py-vs-importing-fixtures-from-dedicate-modules. I tried adding some functions and test_email_token_and_registration_confirmation_email() fixture into one file and I am still getting a very similar error.

example 3

In example 3 instead of a function for def test_username_db(): I am using a fixture

test_function.py

Also I wrote the database class here.

import fixture

@pytest.fixture 
def test_username_db():
    #  assume bob exists 
    user_db = User.query.filter_by(username='Bob').first() 
    assert user_db != 'Bob'  

# other fixtures...

conftest.py

from tests.test_function import test_username_db ...

 __all__ = ['test_username_db'] 

@pytest.fixture() 
def create_db(new_user, test_username_db):
    
    bind_key="testing_app_db"
    # Create the database and the database table
    db.create_all(bind_key)
    
    db.session.add(new_user)
    db.session.commit()
    
    # yield unlike return doesn't stop when called.
  
    yield test_username_db() 
    yield # other functions

    db.drop_all(bind_key) 

test_fixture.py

test_fixture.py(create_db)
    create_db()

Here is the exact error for example 3.

python -m pytest
================================================================= test session starts ==================================================================
platform win32 -- Python 3.10.8, pytest-7.1.2, pluggy-1.0.0
rootdir: C:\Users\nmyle\OneDrive\Desktop\flaskcodeusethis\flaskblog2
collected 0 items / 1 error

======================================================================== ERRORS ======================================================================== 
____________________________________________________________ ERROR collecting test session _____________________________________________________________ 
..\..\..\..\Anaconda3\envs\py\lib\importlib\__init__.py:126: in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
<frozen importlib._bootstrap>:1050: in _gcd_import
    ???
<frozen importlib._bootstrap>:1027: in _find_and_load
    ???
<frozen importlib._bootstrap>:1006: in _find_and_load_unlocked
    ???
<frozen importlib._bootstrap>:688: in _load_unlocked
    ???
..\..\..\..\Anaconda3\envs\py\lib\site-packages\_pytest\assertion\rewrite.py:168: in exec_module
    exec(co, module.__dict__)
app\tests\conftest.py:5: in <module>
    from tests.functions_use_db import app, db, UserTest , email_token_and_registration_confirmation_email
E   ModuleNotFoundError: No module named 'tests'
=============================================================== short test summary info ================================================================ 
ERROR  - ModuleNotFoundError: No module named 'tests'
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 

Like stated earlier how do I fix this?

Focusing on example 3, it may have something to do w/ the way Pytest loads the modules. When I reference my test module in my conftest.py file, I ran into errors. I would suggest writing the code to instantiate your database in another module other than the test module (maybe in your contest.py module). Also, I put all of my fixtures in my conftest module. So your code would look similar to this.

test_functions.py

#pass your fixture name as a parameter
def test_username_db(create_db):
    #reference your fixture in this function to call it 
    db_usr_name = create_db("Bob")
    assert db_usr_name != 'Bob'

conftest.py

import pytest

@pytest.fixture() 
def create_db():
    def _subfunc(new_user):
        
        #code to create your db here
        
        return db.user_name 
        
    yield 
    #do your tear down functions here (don't reference any functions in your test_functions.py module)

On fixtures, I use sub functions for parameters because it seems you can't use parameter like normal functions on fixtures (see here).

Sidenote: Your test will fail if the database correctly adds "Bob" as a new user. I don't know if that's what you intended.