Function get_callable_argspec

lib/sqlalchemy/util/langhelpers.py:461–518

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.

(
    fn: Callable[..., Any], no_self: bool = False, _is_init: bool = False
)

def get_callable_argspec(
    fn: Callable[..., Any], no_self: bool = False, _is_init: bool = False
) -> compat.FullArgSpec:
    """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) or (
        hasattr(fn, "__code__")
        and not inspect.isclass(fn)
        and not inspect.ismethod(fn)
    ):
        if _is_init and no_self:
            spec = compat.inspect_getfullargspec(fn)
            return compat.FullArgSpec(
                spec.args[1:],
                spec.varargs,
                spec.varkw,
                spec.defaults,
                spec.kwonlyargs,
                spec.kwonlydefaults,
                spec.annotations,
            )
        else:
            return compat.inspect_getfullargspec(fn)
    elif inspect.ismethod(fn):
        if no_self and (_is_init or fn.__self__):
            spec = compat.inspect_getfullargspec(fn.__func__)
            return compat.FullArgSpec(
                spec.args[1:],
                spec.varargs,
                spec.varkw,
                spec.defaults,
                spec.kwonlyargs,
                spec.kwonlydefaults,
                spec.annotations,
            )
        else:
            return compat.inspect_getfullargspec(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_getfullargspec(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)