Just some musings about decorators

decorators.py

from functools import wraps
STRING1_LIST = ['A', 'B', 'C']
STRING2_LIST = ['D', 'E', 'F']
def type_checker(int1=None, string1=None, string2=None):
    """ Decorator function to check if int1 is an int and
        that string1 or string2 supplied is actually a valid string
    """
    if string1:
        s = 'string1'
        list_to_find_in = STRING1_LIST
    if string2:
        s = 'string2'
        list_to_find_in = STRING2_LIST
    obj = string1 or string2
    try:
        int1 = int(int1)
    except ValueError:
        bottle.response.status = 400
        return {"status": "error", "message": "int1 could not be converted to int."}
    if obj not in list_to_find_in:
        bottle.response.status = 400
        return {"status": "error", "message": "Invalid {} name:{}. Must be one of:{}".format(s, obj, list_to_find_in)}
    return None

def invalid_arg_catcher(your_type_checker_here):
    """ Decorator to implement a type checker """
    def decorator_outer(func):
        @wraps(func)
        def wrapper(*args, **kwargs):
            caught = your_type_checker_here(**kwargs)
            if caught:
                return caught
            return func(*args, **kwargs)
        return wrapper
    return decorator_outer


@app.get('/<int1>/<string1>')
@invalid_arg_catcher(type_checker)
@authentication_decorator
def _get(int1, string1):

Decorator to implement some custom type checking for a bottle endpoint.