Pytest cannot import source file. What am I doing wrong?

Question

This is my folder structure:

 tree -L 2
.
├── Pipfile
├── Pipfile.lock
├── Procfile
├── README.md
├── __init__.py
├── __pycache__
│   └── __init__.cpython-37.pyc
├── alembic
│   ├── README
│   ├── env.py
│   ├── script.py.mako
│   └── versions
├── clients
│   ├── __init__.py
│   ├── __pycache__
│   ├── binance_client.py
│   └── slack_client.py
├── helpers
│   ├── __init__.py
│   ├── __pycache__
│   └── math_helpers.py
├── models
│   ├── __init__.py
│   ├── __pycache__
│   ├── pair.py
├── requirements.txt
├── tests
│   ├── __init__.py
│   ├── __pycache__
│   └── test_pair.py

When I run this test in the tests folder:

from models.pair import Pair


def test_name():
    coin = "some_coin"
    underlying_asset = "BTC"
    pair = Pair(coin, underlying_asset)
    print(pair)

I get an error.

ImportError while importing test module '/Users/stride-admin/kittycapital/tests/test_pair.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
tests/test_pair.py:1: in <module>
    from models.pair import Pair
E   ModuleNotFoundError: No module named 'models'
=========================================================================================================================== short test summary info ============================================================================================================================
ERROR tests/test_pair.py
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

In the root directory (same level as clients, tests, models) when I run pytest I get the above error. What am I doing wrong?

When I do this in my test file:

from ..models.pair import Pair


def test_name():
    coin = "some_coin"
    underlying_asset = "BTC"
    pair = Pair(coin, underlying_asset)
    print(pair)

I get this error:

ImportError while importing test module '/Users/stride-admin/kittycapital/tests/test_pair.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
tests/test_pair.py:1: in <module>
    from ..models.pair import Pair
models/pair.py:1: in <module>
    from clients.binance_client import BinanceClient, BinanceAPIError
E   ModuleNotFoundError: No module named 'clients'

So that feels wrong.