ensure_paths_exist.py

"""
file: /tmp/qwer.py

>>> @ensure_paths_exist
... def a(p: Path, *a, pp: Path): pass
...
>>> a('/tmp/qwer', pp='/tmp/qwer.py')
>>> a('/tmp/qwer.py', 1,2, pp='/tmp/qwer')
Traceback (most recent call last):
  ...
FileNotFoundError: No such file or directory: '/tmp/qwer'
"""

from pathlib import Path

def ensure_paths_exist(func):
    """
    Ensure annotated paths exist.
    """
    #print(dir(func))
    #print(func.__annotations__)
    path_keys = [k for k, t in func.__annotations__.items() if issubclass(t, Path)]
    from functools import wraps
    @wraps(func)
    def _func(*a, **kw):
        for k, v in kw.items():
            if k in path_keys and not Path(v).exists():
                raise FileNotFoundError(f'No such file or directory: {repr(v)}')
        return func(*a, **kw)

    #print(_func.__name__)
    #print(_func.__doc__)
    return _func