TypeError: __init__() missing 1 required positional argument: 'units' code example

Example 1: TypeError: __init__() missing 1 required positional argument: 'on_delete'

categorie = models.ForeignKey(
    'Categorie',
    on_delete=models.CASCADE,
)

Example 2: TypeError: __init__() missing 1 required positional argument: 'denom' in unit testing python site:stackoverflow.com

RecursionError: maximum recursion depth exceeded