django_reverse_engineer_modelform.py

import inspect, types

verboten = set(["queryset", "initial", "error_messages"])
NotNone = object()
memo = set()
def _make_ctor_args(obj):
	params = []
	namesSeen = set()
	allArgs = []
	for cls in inspect.getmro(obj.__class__):
		ctor = cls.__init__
		if cls == object or not isinstance(ctor, types.MethodType):
			continue
		args, _, _, defs = inspect.getargspec(ctor)
		if not defs:
			defs = [NotNone] * len(args)
		for arg, default in zip(args, defs)[1:]:
			if arg not in namesSeen:
				allArgs.append((arg, default))
				namesSeen.add(arg)
	for arg, default in allArgs:
		val = getattr(obj, arg, None)
		if arg not in verboten and val != default:
			r = repr(val)
			if isinstance(val, list):
				r = "[%s]" % ", ".join(make_full_ctor(v) for v in val)
			elif r.startswith("<"): # Non-canonical, attempt to recurse ctor
				r = make_full_ctor(val)
			
			params.append("%s = %s" % (arg, r))
	return ", ".join(params)

def make_full_ctor(obj):
	i = id(obj)
	if i in memo:
		return repr(obj)
	memo.add(i)
	qname = "%s.%s" % (
		obj.__class__.__module__,
		obj.__class__.__name__
	)
	return "%s(%s)" % (qname, _make_ctor_args(obj))

def reverse_engineer_modelform(form_class):
	inst = form_class()
	print "class %s(forms.ModelForm):" % (form_class.__name__)
	for name, field in sorted(inst.fields.iteritems(), key = lambda (n,f): f.creation_counter):
		print "\t%s = %s" % (name, make_full_ctor(field))