multiparameter_callback.py

#!/usr/bin/env python3

from inspect import _empty, signature


def get_multiparameter_callback(callback, **parameters):
    callback_sig_p = signature(callback).parameters
    # If some provider parameter does not belong to callback parameters.
    unexpected_parameters = list(parameters.keys() - callback_sig_p.keys())
    if len(unexpected_parameters) > 0:
        raise TypeError(
            f"{callback.__name__}() got the following unexpected keyword "
            f"arguments: '{', '.join(unexpected_parameters)}'"
            )

    required_empty_parameters = list(
            set(
                [
                    callback_sig_p[i].name for i in callback_sig_p
                    if callback_sig_p[i].default == _empty
                ]
            ) - set(parameters)
        )

    if len(required_empty_parameters) > 0:
        raise TypeError(
            f"TypeError: {callback.__name__}() missing "
            f"{len(required_empty_parameters)} required "
            "positional argument(s): "
            f"'{', '.join(required_empty_parameters)}'"
            )

    list_of_parameters = []
    # For each parameter in the provided callback.
    for p in callback_sig_p.keys():
        if p in parameters.keys():
            # If parameter is in provided parameters we append it to
            # list of parameters.
            list_of_parameters.append(parameters[p])
        else:
            # Else we try to get the default value of the function.
            default_value = callback_sig_p[p].default
            if default_value == _empty:
                raise SyntaxError(
                    "non-default argument follows default argument"
                    )
            list_of_parameters.append(default_value)

    return lambda parameter: callback(*parameter), list_of_parameters