DeepDiff 6.2.0 documentation!

Basics

Importing

>>> from deepdiff import DeepDiff
>>> from pprint import pprint

Same object returns empty

>>> t1 = {1:1, 2:2, 3:3}
>>> t2 = t1
>>> print(DeepDiff(t1, t2))
{}

Type of an item has changed

>>> t1 = {1:1, 2:2, 3:3}
>>> t2 = {1:1, 2:"2", 3:3}
>>> pprint(DeepDiff(t1, t2), indent=2)
{ 'type_changes': { 'root[2]': { 'new_type': <class 'str'>,
                                 'new_value': '2',
                                 'old_type': <class 'int'>,
                                 'old_value': 2}}}

Value of an item has changed

>>> t1 = {1:1, 2:2, 3:3}
>>> t2 = {1:1, 2:4, 3:3}
>>> pprint(DeepDiff(t1, t2, verbose_level=0), indent=2)
{'values_changed': {'root[2]': {'new_value': 4, 'old_value': 2}}}

Item added and/or removed

>>> t1 = {1:1, 3:3, 4:4}
>>> t2 = {1:1, 3:3, 5:5, 6:6}
>>> ddiff = DeepDiff(t1, t2)
>>> pprint (ddiff)
{'dictionary_item_added': [root[5], root[6]],
 'dictionary_item_removed': [root[4]]}

Set verbose level to 2 in order to see the added or removed items with their values

>>> t1 = {1:1, 3:3, 4:4}
>>> t2 = {1:1, 3:3, 5:5, 6:6}
>>> ddiff = DeepDiff(t1, t2, verbose_level=2)
>>> pprint(ddiff, indent=2)
{ 'dictionary_item_added': {'root[5]': 5, 'root[6]': 6},
  'dictionary_item_removed': {'root[4]': 4}}

String difference

>>> t1 = {1:1, 2:2, 3:3, 4:{"a":"hello", "b":"world"}}
>>> t2 = {1:1, 2:4, 3:3, 4:{"a":"hello", "b":"world!"}}
>>> ddiff = DeepDiff(t1, t2)
>>> pprint (ddiff, indent = 2)
{ 'values_changed': { 'root[2]': {'new_value': 4, 'old_value': 2},
                      "root[4]['b']": { 'new_value': 'world!',
                                        'old_value': 'world'}}}

String difference 2

>>> t1 = {1:1, 2:2, 3:3, 4:{"a":"hello", "b":"world!\nGoodbye!\n1\n2\nEnd"}}
>>> t2 = {1:1, 2:2, 3:3, 4:{"a":"hello", "b":"world\n1\n2\nEnd"}}
>>> ddiff = DeepDiff(t1, t2)
>>> pprint (ddiff, indent = 2)
{ 'values_changed': { "root[4]['b']": { 'diff': '--- \n'
                                                '+++ \n'
                                                '@@ -1,5 +1,4 @@\n'
                                                '-world!\n'
                                                '-Goodbye!\n'
                                                '+world\n'
                                                ' 1\n'
                                                ' 2\n'
                                                ' End',
                                        'new_value': 'world\n1\n2\nEnd',
                                        'old_value': 'world!\n'
                                                     'Goodbye!\n'
                                                     '1\n'
                                                     '2\n'
                                                     'End'}}}

>>>
>>> print (ddiff['values_changed']["root[4]['b']"]["diff"])
---
+++
@@ -1,5 +1,4 @@
-world!
-Goodbye!
+world
 1
 2
 End

List difference

>>> 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)
>>> pprint (ddiff, indent = 2)
{'iterable_item_removed': {"root[4]['b'][2]": 3, "root[4]['b'][3]": 4}}

List that contains dictionary:

>>> t1 = {1:1, 2:2, 3:3, 4:{"a":"hello", "b":[1, 2, {1:1, 2:2}]}}
>>> t2 = {1:1, 2:2, 3:3, 4:{"a":"hello", "b":[1, 2, {1:3}]}}
>>> ddiff = DeepDiff(t1, t2)
>>> pprint (ddiff, indent = 2)
{ 'dictionary_item_removed': [root[4]['b'][2][2]],
  'values_changed': {"root[4]['b'][2][1]": {'new_value': 3, 'old_value': 1}}}

Sets:

>>> t1 = {1, 2, 8}
>>> t2 = {1, 2, 3, 5}
>>> ddiff = DeepDiff(t1, t2)
>>> pprint(ddiff)
{'set_item_added': [root[3], root[5]], 'set_item_removed': [root[8]]}

Named Tuples:

>>> from collections import namedtuple
>>> Point = namedtuple('Point', ['x', 'y'])
>>> t1 = Point(x=11, y=22)
>>> t2 = Point(x=11, y=23)
>>> pprint (DeepDiff(t1, t2))
{'values_changed': {'root.y': {'new_value': 23, 'old_value': 22}}}

Custom objects:

>>> class ClassA(object):
...     a = 1
...     def __init__(self, b):
...         self.b = b
...
>>> t1 = ClassA(1)
>>> t2 = ClassA(2)
>>>
>>> pprint(DeepDiff(t1, t2))
{'values_changed': {'root.b': {'new_value': 2, 'old_value': 1}}}

Object attribute added:

>>> t2.c = "new attribute"
>>> pprint(DeepDiff(t1, t2))
{'attribute_added': [root.c],
 'values_changed': {'root.b': {'new_value': 2, 'old_value': 1}}}

Note

All the examples above use the default Text View. If you want traversing functionality in the results, use the Tree View. You just need to set view=’tree’ to get it in tree form.

Group By

group_by can be used when dealing with list of dictionaries to convert them to group them by value defined in group_by. The common use case is when reading data from a flat CSV and primary key is one of the columns in the CSV. We want to use the primary key to group the rows instead of CSV row number.

Example:

>>> from deepdiff import DeepDiff
>>> t1 = [
...     {'id': 'AA', 'name': 'Joe', 'last_name': 'Nobody'},
...     {'id': 'BB', 'name': 'James', 'last_name': 'Blue'},
...     {'id': 'CC', 'name': 'Mike', 'last_name': 'Apple'},
... ]
>>>
>>> t2 = [
...     {'id': 'AA', 'name': 'Joe', 'last_name': 'Nobody'},
...     {'id': 'BB', 'name': 'James', 'last_name': 'Brown'},
...     {'id': 'CC', 'name': 'Mike', 'last_name': 'Apple'},
... ]
>>>
>>> DeepDiff(t1, t2)
{'values_changed': {"root[1]['last_name']": {'new_value': 'Brown', 'old_value': 'Blue'}}}

Now we use group_by=’id’:

>>> DeepDiff(t1, t2, group_by='id')
{'values_changed': {"root['BB']['last_name']": {'new_value': 'Brown', 'old_value': 'Blue'}}}

Note

group_by actually changes the structure of the t1 and t2. You can see this by using the tree view:

>>> diff = DeepDiff(t1, t2, group_by='id', view='tree')
>>> diff
{'values_changed': [<root['BB']['last_name'] t1:'Blue', t2:'Brown'>]}
>>> diff['values_changed'][0]
<root['BB']['last_name'] t1:'Blue', t2:'Brown'>
>>> diff['values_changed'][0].up
<root['BB'] t1:{'name': 'Ja...}, t2:{'name': 'Ja...}>
>>> diff['values_changed'][0].up.up
<root t1:{'AA': {'nam...}, t2:{'AA': {'nam...}>
>>> diff['values_changed'][0].up.up.t1
{'AA': {'name': 'Joe', 'last_name': 'Nobody'}, 'BB': {'name': 'James', 'last_name': 'Blue'}, 'CC': {'name': 'Mike', 'last_name': 'Apple'}}

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