def _get_flattener(self, obj):
if util.is_primitive(obj):
return lambda obj: obj
list_recurse = self._list_recurse
if util.is_list(obj):
if self._mkref(obj):
return list_recurse
else:
self._push()
return self._getref
# We handle tuples and sets by encoding them in a "(tuple|set)dict"
if util.is_tuple(obj):
if not self.unpicklable:
return list_recurse
return lambda obj: {tags.TUPLE: [self._flatten(v) for v in obj]}
if util.is_set(obj):
if not self.unpicklable:
return list_recurse
return lambda obj: {tags.SET: [self._flatten(v) for v in obj]}
if util.is_dictionary(obj):
return self._flatten_dict_obj
if util.is_type(obj):
return _mktyperef
if util.is_object(obj):
return self._ref_obj_instance
if util.is_module_function(obj):
return self._flatten_function
# instance methods, lambdas, old style classes...
self._pickle_warning(obj)
return None
def _flatten_dict_obj(self, obj, data=None):
"""Recursively call flatten() and return json-friendly dict
"""
if data is None:
data = obj.__class__()
flatten = self._flatten_key_value_pair
for k, v in sorted(obj.items(), key=util.itemgetter):
flatten(k, v, data)
# the collections.defaultdict protocol
if hasattr(obj, 'default_factory') and callable(obj.default_factory):
factory = obj.default_factory
if util.is_type(factory):
# Reference the type
value = _mktyperef(factory)
else:
# Create an instance from the factory and assume that the
# resulting instance is a suitable examplar.
value = self._flatten(handlers.CloneFactory(factory()))
data['default_factory'] = value
return data
