traitlets/getargspec.py

# -*- coding: utf-8 -*-
"""
    getargspec excerpted from:
    
    sphinx.util.inspect
    ~~~~~~~~~~~~~~~~~~~
    Helpers for inspecting Python modules.
    :copyright: Copyright 2007-2015 by the Sphinx team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""

import inspect
from IPython.utils.py3compat import PY3

# Unmodified from sphinx below this line

if PY3:
    from functools import partial

    def getargspec(func):
        """Like inspect.getargspec but supports functools.partial as well."""
        if inspect.ismethod(func):
            func = func.__func__
        if type(func) is partial:
            orig_func = func.func
            argspec = getargspec(orig_func)
            args = list(argspec[0])
            defaults = list(argspec[3] or ())
            kwoargs = list(argspec[4])
            kwodefs = dict(argspec[5] or {})
            if func.args:
                args = args[len(func.args):]
            for arg in func.keywords or ():
                try:
                    i = args.index(arg) - len(args)
                    del args[i]
                    try:
                        del defaults[i]
                    except IndexError:
                        pass
                except ValueError:   # must be a kwonly arg
                    i = kwoargs.index(arg)
                    del kwoargs[i]
                    del kwodefs[arg]
            return inspect.FullArgSpec(args, argspec[1], argspec[2],
                                       tuple(defaults), kwoargs,
                                       kwodefs, argspec[6])
        while hasattr(func, '__wrapped__'):
            func = func.__wrapped__
        if not inspect.isfunction(func):
            raise TypeError('%r is not a Python function' % func)
        return inspect.getfullargspec(func)

else:  # 2.6, 2.7
    from functools import partial

    def getargspec(func):
        """Like inspect.getargspec but supports functools.partial as well."""
        if inspect.ismethod(func):
            func = func.__func__
        parts = 0, ()
        if type(func) is partial:
            keywords = func.keywords
            if keywords is None:
                keywords = {}
            parts = len(func.args), keywords.keys()
            func = func.func
        if not inspect.isfunction(func):
            raise TypeError('%r is not a Python function' % func)
        args, varargs, varkw = inspect.getargs(func.__code__)
        func_defaults = func.__defaults__
        if func_defaults is None:
            func_defaults = []
        else:
            func_defaults = list(func_defaults)
        if parts[0]:
            args = args[parts[0]:]
        if parts[1]:
            for arg in parts[1]:
                i = args.index(arg) - len(args)
                del args[i]
                try:
                    del func_defaults[i]
                except IndexError:
                    pass
        return inspect.ArgSpec(args, varargs, varkw, func_defaults)