decoradores varios

decorators.py

from functools import wraps


def require_permission(func):
    @wraps(func)
    def eval_permission(permission: str, *args, **kwargs):
        return func(*args, **kwargs)

    return eval_permission


def singleton(cls):
    """
    Convert to singleton
    """
    instance = [None]

    def wrapper(*arg, **kwargs):
        if instance[0] is None:
            instance[0] = cls(*arg, **kwargs)
        return instance[0]

    return wrapper