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sepermanseperman
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Merge pull request #458 from sf-tcalhoun/delta_constructor_fix
Delta constructor fix for flat_dict_list param (pull request back to dev branch)
2 parents 71fde30 + a9bfc08 commit 32e62bf

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‎deepdiff/delta.py

+3-1
Original file line numberDiff line numberDiff line change
@@ -1,3 +1,4 @@
1+
import copy
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import logging
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from functools import partial
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from collections.abc import Mapping
@@ -125,7 +126,8 @@ def _deserializer(obj, safe_to_import=None):
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raise ValueError(BINIARY_MODE_NEEDED_MSG.format(e)) from None
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self.diff = _deserializer(content, safe_to_import=safe_to_import)
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elif flat_dict_list:
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self.diff = self._from_flat_dicts(flat_dict_list)
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# Use copy to preserve original value of flat_dict_list in calling module
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self.diff = self._from_flat_dicts(copy.deepcopy(flat_dict_list))
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else:
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raise ValueError(DELTA_AT_LEAST_ONE_ARG_NEEDED)
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‎tests/test_delta.py

+150
Original file line numberDiff line numberDiff line change
@@ -1,3 +1,5 @@
1+
import copy
2+
13
import pytest
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import os
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import io
@@ -461,6 +463,154 @@ def test_delta_dict_items_added_retain_order(self):
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delta2 = Delta(diff=diff, bidirectional=True)
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assert t1 == t2 - delta2
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466+
def test_delta_constr_flat_dict_list_param_preserve(self):
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"""
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Issue: https://github.com/seperman/deepdiff/issues/457
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Scenario:
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We found that when a flat_dict_list was provided as a constructor
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parameter for instantiating a new delta, the provided flat_dict_list
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is unexpectedly being mutated/changed, which can be troublesome for the
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caller if they were expecting the flat_dict_list to be used BY COPY
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rather than BY REFERENCE.
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Intent:
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Preserve the original value of the flat_dict_list variable within the
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calling module/function after instantiating the new delta.
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"""
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t1 = {
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"individualNames": [
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{
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"firstName": "Johnathan",
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"lastName": "Doe",
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"prefix": "COLONEL",
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"middleName": "A",
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"primaryIndicator": True,
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"professionalDesignation": "PHD",
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"suffix": "SR",
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"nameIdentifier": "00001"
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},
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{
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"firstName": "John",
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"lastName": "Doe",
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"prefix": "",
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"middleName": "",
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"primaryIndicator": False,
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"professionalDesignation": "",
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"suffix": "SR",
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"nameIdentifier": "00002"
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}
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]
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}
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t2 = {
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"individualNames": [
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{
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"firstName": "Johnathan",
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"lastName": "Doe",
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"prefix": "COLONEL",
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"middleName": "A",
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"primaryIndicator": True,
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"professionalDesignation": "PHD",
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"suffix": "SR",
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"nameIdentifier": "00001"
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},
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{
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"firstName": "Johnny",
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"lastName": "Doe",
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"prefix": "",
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"middleName": "A",
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"primaryIndicator": False,
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"professionalDesignation": "",
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"suffix": "SR",
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"nameIdentifier": "00003"
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}
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]
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}
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def compare_func(item1, item2, level=None):
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print("*** inside compare ***")
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it1_keys = item1.keys()
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try:
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# --- individualNames ---
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if 'nameIdentifier' in it1_keys and 'lastName' in it1_keys:
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match_result = item1['nameIdentifier'] == item2['nameIdentifier']
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print("individualNames - matching result:", match_result)
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return match_result
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else:
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print("Unknown list item...", "matching result:", item1 == item2)
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return item1 == item2
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except Exception:
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raise CannotCompare() from None
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# ---------------------------- End of nested function
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# This diff should show:
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# 1 - list item (with an index on the path) being added
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# 1 - list item (with an index on the path) being removed
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diff = DeepDiff(t1, t2, report_repetition=True,
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ignore_order=True, iterable_compare_func=compare_func, cutoff_intersection_for_pairs=1)
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# Now create a flat_dict_list from a delta instantiated from the diff...
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temp_delta = Delta(diff, always_include_values=True, bidirectional=True, raise_errors=True)
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flat_dict_list = temp_delta.to_flat_dicts()
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# Note: the list index is provided on the path value...
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assert flat_dict_list == [{'path': ['individualNames', 1],
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'value': {'firstName': 'Johnny',
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'lastName': 'Doe',
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'prefix': '',
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'middleName': 'A',
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'primaryIndicator': False,
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'professionalDesignation': '',
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'suffix': 'SR',
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'nameIdentifier': '00003'},
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'action': 'unordered_iterable_item_added'},
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{'path': ['individualNames', 1],
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'value': {'firstName': 'John',
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'lastName': 'Doe',
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'prefix': '',
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'middleName': '',
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'primaryIndicator': False,
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'professionalDesignation': '',
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'suffix': 'SR',
579+
'nameIdentifier': '00002'},
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'action': 'unordered_iterable_item_removed'}]
581+
582+
preserved_flat_dict_list = copy.deepcopy(flat_dict_list) # Use this later for assert comparison
583+
584+
# Now use the flat_dict_list to instantiate a new delta...
585+
delta = Delta(flat_dict_list=flat_dict_list,
586+
always_include_values=True, bidirectional=True, raise_errors=True)
587+
588+
# if the flat_dict_list is (unexpectedly) mutated, it will be missing the list index number on the path value.
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old_mutated_list_missing_indexes_on_path = [{'path': ['individualNames'],
590+
'value': {'firstName': 'Johnny',
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'lastName': 'Doe',
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'prefix': '',
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'middleName': 'A',
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'primaryIndicator': False,
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'professionalDesignation': '',
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'suffix': 'SR',
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'nameIdentifier': '00003'},
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'action': 'unordered_iterable_item_added'},
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{'path': ['individualNames'],
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'value': {'firstName': 'John',
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'lastName': 'Doe',
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'prefix': '',
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'middleName': '',
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'primaryIndicator': False,
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'professionalDesignation': '',
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'suffix': 'SR',
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'nameIdentifier': '00002'},
608+
'action': 'unordered_iterable_item_removed'}]
609+
610+
# Verify that our fix in the delta constructor worked...
611+
assert flat_dict_list != old_mutated_list_missing_indexes_on_path
612+
assert flat_dict_list == preserved_flat_dict_list
613+
464614

465615
picklalbe_obj_without_item = PicklableClass(11)
466616
del picklalbe_obj_without_item.item

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