langhelpers.py 文件源码

def get_callable_argspec(fn, no_self=False, _is_init=False):
    """Return the argument signature for any callable.

    All pure-Python callables are accepted, including
    functions, methods, classes, objects with __call__;
    builtins and other edge cases like functools.partial() objects
    raise a TypeError.

    """
    if inspect.isbuiltin(fn):
        raise TypeError("Can't inspect builtin: %s" % fn)
    elif inspect.isfunction(fn):
        if _is_init and no_self:
            spec = compat.inspect_getargspec(fn)
            return compat.ArgSpec(spec.args[1:], spec.varargs,
                                  spec.keywords, spec.defaults)
        else:
            return compat.inspect_getargspec(fn)
    elif inspect.ismethod(fn):
        if no_self and (_is_init or fn.__self__):
            spec = compat.inspect_getargspec(fn.__func__)
            return compat.ArgSpec(spec.args[1:], spec.varargs,
                                  spec.keywords, spec.defaults)
        else:
            return compat.inspect_getargspec(fn.__func__)
    elif inspect.isclass(fn):
        return get_callable_argspec(
            fn.__init__, no_self=no_self, _is_init=True)
    elif hasattr(fn, '__func__'):
        return compat.inspect_getargspec(fn.__func__)
    elif hasattr(fn, '__call__'):
        if inspect.ismethod(fn.__call__):
            return get_callable_argspec(fn.__call__, no_self=no_self)
        else:
            raise TypeError("Can't inspect callable: %s" % fn)
    else:
        raise TypeError("Can't inspect callable: %s" % fn)