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:doc:`/index`

F.A.Q

Note

|:mega:| Please fill out our fast 5-question survey so that we can learn how & why you use DeepDiff, and what improvements we should make. Thank you! |:dancers:|

Q: DeepDiff report is not precise when ignore_order=True

>>> from deepdiff import DeepDiff
>>> from pprint import pprint
>>> t1 = [
...     {
...         "key": "some/pathto/customers/foo/",
...         "flags": 0,
...         "value": ""
...     },
...     {
...         "key": "some/pathto/customers/foo/account_number",
...         "flags": 0,
...         "value": "somevalue1"
...     }
... ]
>>>
>>> t2 = [
...     {
...         "key": "some/pathto/customers/foo/account_number",
...         "flags": 0,
...         "value": "somevalue2"
...     },
...     {
...         "key": "some/pathto/customers/foo/",
...         "flags": 0,
...         "value": "new"
...     }
... ]
>>>
>>> pprint(DeepDiff(t1, t2))
{'values_changed': {"root[0]['key']": {'new_value': 'some/pathto/customers/foo/account_number',
                                       'old_value': 'some/pathto/customers/foo/'},
                    "root[0]['value']": {'new_value': 'somevalue2',
                                         'old_value': ''},
                    "root[1]['key']": {'new_value': 'some/pathto/customers/foo/',
                                       'old_value': 'some/pathto/customers/foo/account_number'},
                    "root[1]['value']": {'new_value': 'new',
                                         'old_value': 'somevalue1'}}}

Answer

This is explained in :ref:`cutoff_distance_for_pairs_label` and :ref:`cutoff_intersection_for_pairs_label`

Bump up these 2 parameters to 1 and you get what you want:

>>> pprint(DeepDiff(t1, t2, ignore_order=True, cutoff_distance_for_pairs=1, cutoff_intersection_for_pairs=1))
{'values_changed': {"root[0]['value']": {'new_value': 'new', 'old_value': ''},
                    "root[1]['value']": {'new_value': 'somevalue2',
                                         'old_value': 'somevalue1'}}}

Q: The report of changes in a nested dictionary is too granular

Answer

Use :ref:`threshold_to_diff_deeper_label`

>>> from deepdiff import DeepDiff
>>> t1 = {"veggie": "carrots"}
>>> t2 = {"meat": "carrots"}
>>>
>>> DeepDiff(t1, t2, threshold_to_diff_deeper=0)
{'dictionary_item_added': ["root['meat']"], 'dictionary_item_removed': ["root['veggie']"]}
>>> DeepDiff(t1, t2, threshold_to_diff_deeper=0.33)
{'values_changed': {'root': {'new_value': {'meat': 'carrots'}, 'old_value': {'veggie': 'carrots'}}}}

Q: TypeError: Object of type type is not JSON serializable

I'm trying to serialize the DeepDiff results into json and I'm getting the TypeError.

>>> diff=DeepDiff(1, "a")
>>> diff
{'type_changes': {'root': {'old_type': <class 'int'>, 'new_type': <class 'str'>, 'old_value': 1, 'new_value': 'a'}}}
>>> json.dumps(diff)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File ".../json/__init__.py", line 231, in dumps
    return _default_encoder.encode(obj)
  File ".../json/encoder.py", line 199, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File ".../json/encoder.py", line 257, in iterencode
    return _iterencode(o, 0)
  File ".../json/encoder.py", line 179, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type type is not JSON serializable

Answer

In order to serialize DeepDiff results into json, use to_json()

>>> diff.to_json()
'{"type_changes": {"root": {"old_type": "int", "new_type": "str", "old_value": 1, "new_value": "a"}}}'

Q: How do I parse DeepDiff result paths?

Answer

Use parse_path:

>>> from deepdiff import parse_path
>>> parse_path("root[1][2]['age']")
[1, 2, 'age']
>>> parse_path("root[1][2]['age']", include_actions=True)
[{'element': 1, 'action': 'GET'}, {'element': 2, 'action': 'GET'}, {'element': 'age', 'action': 'GET'}]
>>>
>>> parse_path("root['joe'].age")
['joe', 'age']
>>> parse_path("root['joe'].age", include_actions=True)
[{'element': 'joe', 'action': 'GET'}, {'element': 'age', 'action': 'GETATTR'}]

Or use the tree view so you can use path(output_format='list'):

>>> t1 = {1:1, 2:2, 3:3, 4:{"a":"hello", "b":[1, 2, 3, 4]}}
>>> t2 = {1:1, 2:2, 3:3, 4:{"a":"hello", "b":[1, 2]}}
>>> ddiff = DeepDiff(t1, t2, view='tree')
>>> ddiff
{'iterable_item_removed': [<root[4]['b'][2] t1:3, t2:not present>, <root[4]['b'][3] t1:4, t2:not present>]}
>>> # Note that the iterable_item_removed is a set. In this case it has 2 items in it.
>>> # One way to get one item from the set is to convert it to a list
>>> # And then get the first item of the list:
>>> removed = list(ddiff['iterable_item_removed'])[0]
>>> removed
<root[4]['b'][2] t1:3, t2:not present>
>>>
>>> parent = removed.up
>>> parent
<root[4]['b'] t1:[1, 2, 3, 4], t2:[1, 2]>
>>> parent.path()  # gives you the string representation of the path
"root[4]['b']"
>>> parent.path(output_format='list')  # gives you the list of keys and attributes that make up the path
[4, 'b']

Q: Why my datetimes are reported in UTC?

Answer

DeepDiff converts all datetimes into UTC. If a datetime is timezone naive, we assume it is in UTC too. That is different than what Python does. Python assumes your timezone naive datetime is in your local timezone. However, you can override it to any other time zone such as your :ref:`default_timezone_label`.

>>> from deepdiff import DeepDiff
>>> from datetime import datetime, timezone
>>> d1 = datetime(2020, 8, 31, 13, 14, 1)
>>> d2 = datetime(2020, 8, 31, 13, 14, 1, tzinfo=timezone.utc)
>>> d1 == d2
False
>>> DeepDiff(d1, d2)
{}
>>> d3 = d2.astimezone(pytz.timezone('America/New_York'))
>>> DeepDiff(d1, d3)
{}
>>> d1 == d3
False

A message from Sep, the creator of DeepDiff

👋 Hi there,

Thank you for using DeepDiff!
As an engineer, I understand the frustration of wrestling with unruly data in pipelines.
That's why I developed a new tool - Qluster to empower non-engineers to control and resolve data issues at scale autonomously and stop bugging the engineers! 🛠️

If you are going through this pain now, I would love to give you early access to Qluster and get your feedback.

Back to :doc:`/index`