testing framework

[larsbuntemeyer]

Just some ideas, could we maybe use a python test framework for data validation? That would be nice, e.g., to generate reports. If we don't want to stop on the first assertion, we could use, e.g.

• unittest, subtests
• pytest-subtests
• allure
• xarray-schema
• tsdat

[larsbuntemeyer]

Example to use subtests:

import unittest

class Car(object):
  def __init__(self, make, model):
    self.make = make
    self.model = make  # Copy and paste error: should be model.
    self.has_seats = True
    self.wheel_count = 3  # Typo: should be 4.

class CarTest(unittest.TestCase):
  def test_init(self):
    make = "Ford"
    model = "Model T"
    car = Car(make=make, model=model)
    with self.subTest(msg='Car.make check'):
        self.assertEqual(car.make, make)
    with self.subTest(msg='Car.model check'):
        self.assertEqual(car.model, model)
    with self.subTest(msg='Car.has_seats check'):
        self.assertTrue(car.has_seats)
    with self.subTest(msg='Car.wheel_count check'):
        self.assertEqual(car.wheel_count, 4)

if __name__ == "__main__":
    unittest.main()

[larsbuntemeyer]

examples using pydantic:

from pydantic import BaseModel, field_validator
class User(BaseModel):
    username: str
    password: str
    age: int
    @field_validator('password')
    def password_must_be_strong(cls, v):
        if len(v) < 16:
            raise ValueError('Password must be at least 16 characters long.')
            return v
    @field_validator('username')
    def username_must_be_strong(cls, v):
        if len(v) < 4:
            raise ValueError('Username must be at least 4 characters long.')
            return v

# Validate incoming user_data
user_data = {'username': 'App', 'password': 'password', 'age': 25}
user = User(**user_data)

[larsbuntemeyer]

it seems that data validation for n-d array/xarray is not really implemented yet. I guess for now, i will simply work with a logger and logging levels...