piddling around with trying to proxy objects to discover their API.

preshow.py

import argparse
import os
import sys
from wrapt import CallableObjectProxy, wrap_object


def _dot_lookup(thing, comp, import_path):
    try:
        return getattr(thing, comp)
    except AttributeError:
        __import__(import_path)
        return getattr(thing, comp)


def _importer(target):
    components = target.split('.')
    import_path = components.pop(0)
    thing = __import__(import_path)

    results = []
    for comp in components:
        import_path += ".%s" % comp
        thing = _dot_lookup(thing, comp, import_path)
        results.append((thing, comp, import_path))
    return results


_NONE = object()


def replace_these(items):
    for item in items:
        imported_target = _importer(item)
        target = imported_target.pop()
        module = imported_target.pop()
        # if target[0] is not _NONE:
        # wrap_object('django.core.management', 'execute_from_command_line', factory=Erm)


def _runscript(filename):
        # The script has to run in __main__ namespace (or imports from
        # __main__ will break).
        #
        # So we clear up the __main__ and set several special variables
        # (this gets rid of pdb's globals and cleans old variables on restarts).
        import __main__
        import __builtin__
        __main__.__dict__.clear()
        __main__.__dict__.update({"__name__"    : "__main__",
                                  "__file__"    : filename,
                                  "__builtins__": __builtin__,
                                 })
        with open(filename, "rb") as fp:
            exec(compile(fp.read(), filename, 'exec'))

def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('--file', '-f', nargs='+')
    known_args = parser.parse_known_args()
    to_replace = known_args[0].file
    remaining_args = known_args[1]
    if remaining_args[0] == '--':
        del remaining_args[0]
    filename = remaining_args[0]
    sys.path[0] = os.path.realpath(os.path.dirname(filename))
    sys.argv = remaining_args
    replace_these(to_replace)
    _runscript(filename)

if __name__ == '__main__':
    main()

showme.py

# -*- coding: utf-8 -*-
from __future__ import unicode_literals, absolute_import
import os
import wrapt


WRAPT_PATH = wrapt.__path__
SITEPACKAGES = os.path.realpath(os.path.dirname(WRAPT_PATH[0]))


def twoddle(key):
    import traceback, sys
    result = traceback.extract_stack()
    internal_frame = result.pop()
    twoddle_frame = result.pop()
    result2 = [result.pop()]
    for filename, lineno, name, line in result2:
        if filename.startswith(SITEPACKAGES):
            filename = filename[len(SITEPACKAGES):].lstrip(os.path.sep)
        print("`%s` by %s via '%s', line %d" % (key, name, filename, lineno))


class showme(wrapt.ObjectProxy):
    def __getattribute__(self, item):
        twoddle(item)
        return super(showme, self).__getattribute__(item)