Function _get_argspec_from_signature

bpython/inspection.py:312–358

Get callable signature from inspect.signature in argspec format. inspect.signature is a Python 3 only function that returns the signature of a function. Its advantage over inspect.getfullargspec is that it returns the signature of a decorated function, if the wrapper function itself is

(f: Callable)

def _get_argspec_from_signature(f: Callable) -> ArgSpec:
    """Get callable signature from inspect.signature in argspec format.

    inspect.signature is a Python 3 only function that returns the signature of
    a function.  Its advantage over inspect.getfullargspec is that it returns
    the signature of a decorated function, if the wrapper function itself is
    decorated with functools.wraps.

    """
    args = []
    varargs = None
    varkwargs = None
    defaults = []
    kwonly = []
    kwonly_defaults = {}
    annotations = {}

    # We use signature here instead of getfullargspec as the latter also returns
    # self and cls (for class methods).
    signature = inspect.signature(f)
    for parameter in signature.parameters.values():
        if parameter.annotation is not parameter.empty:
            annotations[parameter.name] = parameter.annotation

        if parameter.kind == inspect.Parameter.POSITIONAL_OR_KEYWORD:
            args.append(parameter.name)
            if parameter.default is not parameter.empty:
                defaults.append(parameter.default)
        elif parameter.kind == inspect.Parameter.POSITIONAL_ONLY:
            args.append(parameter.name)
        elif parameter.kind == inspect.Parameter.VAR_POSITIONAL:
            varargs = parameter.name
        elif parameter.kind == inspect.Parameter.KEYWORD_ONLY:
            kwonly.append(parameter.name)
            kwonly_defaults[parameter.name] = parameter.default
        elif parameter.kind == inspect.Parameter.VAR_KEYWORD:
            varkwargs = parameter.name

    return ArgSpec(
        args,
        varargs,
        varkwargs,
        defaults if defaults else None,
        kwonly,
        kwonly_defaults if kwonly_defaults else None,
        annotations if annotations else None,
    )


_get_encoding_line_re = LazyReCompile(r"^.*coding[:=]\s*([-\w.]+).*$")