unused parameter bugfix + refactoring

common_helper_mongo/aggregate.py

 import logging
+from typing import List, Optional
+
 from bson.son import SON
 
 
@@ -6,40 +8,32 @@ def get_list_of_all_values(collection, object_path, unwind=False, match=None):
     '''
     Get a list of unique values on a specific object path in a collection.
     An Optional search string (match) can be added.
+    If additional_field is set, all values of this field for each
 
     :param collection: mongo collection to look at
-    :type collection: pymongo.collection
+    :type collection: pymongo.collection.Collection
     :param object_path: mongo object path
     :type object_path: str
     :param unwind: if true: handle list entries as single values
     :type unwind: bool
     :param match: mongo search string
-    :type match: dict
+    :type match: dict, optional
     :return: list
     '''
-    pipeline = []
-    if match is not None:
-        pipeline.append({'$match': match})
-    pipeline.extend([
-        {'$group': {'_id': object_path}},
-        {'$sort': SON([('_id', 1)])}
-    ])
-    if unwind:
-        old_pipe = pipeline
-        pipeline = [{'$unwind': object_path}]
-        pipeline.extend(old_pipe)
+    pipeline = _build_pipeline(object_path, {'_id': object_path}, unwind, SON([('_id', 1)]), match)
     result = _get_list_of_aggregate_list(list(collection.aggregate(pipeline)))
     logging.debug(result)
     return result
 
 
-def get_list_of_all_values_and_collect_information_of_additional_field(collection, object_path, additional_information_object_path, unwind=False, match=None):
+def get_list_of_all_values_and_collect_information_of_additional_field(
+        collection, object_path, additional_information_object_path, unwind=False, match=None):
     '''
     Get a list of unique values and a collection of additional information on a specific object path in a collection.
     An Optional search string (match) can be added.
 
     :param collection: mongo collection to look at
-    :type collection: pymongo.collection
+    :type collection: pymongo.collection.Collection
     :param object_path: mongo object path
     :type object_path: str
     :param additional_information_object_path: field of the additional information
@@ -47,27 +41,41 @@ def get_list_of_all_values_and_collect_information_of_additional_field(collectio
     :param unwind: if true: handle list entries as single values
     :type unwind: bool
     :param match: mongo search string
-    :type match: dict
+    :type match: dict, optional
     :return: {<VALUE>:[<ADDITIONAL_INFORMATION_1>, ...], ...}
     '''
-    pipeline = []
-    if match is not None:
-        pipeline.append({'$match': match})
-    pipeline.extend([
-        {'$group': {'_id': object_path, 'additional_information': {'$addToSet': '$_id'}}},
-        {'$sort': SON([('_id', 1)])}
-    ])
-    if unwind:
-        old_pipe = pipeline
-        pipeline = [{'$unwind': object_path}]
-        pipeline.extend(old_pipe)
+    logging.warning('deprecation warning: this method will be removed in a future release')
+    return get_all_value_combinations_of_fields(collection, object_path, additional_information_object_path, unwind, match)
+
+
+def get_all_value_combinations_of_fields(collection, primary_field, secondary_field, unwind=False, match=None):
+    '''
+    Get a dictionary with all unique values of a field as keys and a list of all unique values that a second field takes
+    on as values (on a specific object path in a collection). An Optional search string (match) can be added.
+
+    :param collection: mongo collection to look at
+    :type collection: pymongo.collection.Collection
+    :param primary_field: mongo object path
+    :type primary_field: str
+    :param secondary_field: field of the additional information
+    :type secondary_field: str
+    :param unwind: if true: handle list entries as single values
+    :type unwind: bool
+    :param match: mongo search string
+    :type match: dict, optional
+    :return: {<VALUE>:[<ADDITIONAL_INFORMATION_1>, ...], ...}
+    '''
+    pipeline = _build_pipeline(
+        primary_field, {'_id': primary_field, 'additional_information': {'$addToSet': secondary_field}},
+        unwind, SON([('_id', 1)]), match
+    )
     result = list(collection.aggregate(pipeline))
-    result = _get_dict_from_aggregat_list(result)
+    result = _get_dict_from_aggregate_list(result)
     logging.debug(result)
     return result
 
 
-def _get_dict_from_aggregat_list(ag_list):
+def _get_dict_from_aggregate_list(ag_list):
     result = {}
     for item in ag_list:
         result[item['_id']] = item['additional_information']
@@ -75,38 +83,26 @@ def _get_dict_from_aggregat_list(ag_list):
 
 
 def _get_list_of_aggregate_list(ag_list):
-    result = []
-    for item in ag_list:
-        result.append(item['_id'])
-    return result
+    return [item['_id'] for item in ag_list]
 
 
 def get_objects_and_count_of_occurrence(collection, object_path, unwind=False, match=None):
     '''
-    Get a list of unique values and their occurences on a specific object path in a collection.
+    Get a list of unique values and their occurrences on a specific object path in a collection.
     An Optional search string (match) can be added.
 
     :param collection: mongo collection to look at
-    :type collection: pymongo.collection
+    :type collection: pymongo.collection.Collection
     :param object_path: mongo object path
     :type object_path: str
     :param unwind: if true: handle list entries as single values
     :type unwind: bool
     :param match: mongo search string
-    :type match: dict
-    :return: [{'_id': <VALUE>, 'count': <OCCURENCES>}, ...]
+    :type match: dict, optional
+    :return: [{'_id': <VALUE>, 'count': <OCCURRENCES>}, ...]
     '''
-    pipeline = []
-    if match is not None:
-        pipeline.append({'$match': match})
-    pipeline.extend([
-        {'$group': {'_id': object_path, 'count': {'$sum': 1}}},
-        {'$sort': SON([('count', -1), ('_id', -1)])}
-    ])
-    if unwind:
-        old_pipe = pipeline
-        pipeline = [{'$unwind': object_path}]
-        pipeline.extend(old_pipe)
+    pipeline = _build_pipeline(object_path, {'_id': object_path, 'count': {'$sum': 1}}, unwind,
+                               SON([('count', -1), ('_id', -1)]), match)
     result = list(collection.aggregate(pipeline))
     logging.debug(result)
     return result
@@ -118,7 +114,7 @@ def get_field_sum(collection, object_path, match=None):
     An Optional search string (match) can be added.
 
     :param collection: mongo collection to look at
-    :type collection: pymongo.collection
+    :type collection: pymongo.collection.Collection
     :param object_path: mongo object path
     :type object_path: str
     :param match: mongo search string
@@ -134,7 +130,7 @@ def get_field_average(collection, object_path, match=None):
     An Optional search string (match) can be added.
 
     :param collection: mongo collection to look at
-    :type collection: pymongo.collection
+    :type collection: pymongo.collection.Collection
     :param object_path: mongo object path
     :type object_path: str
     :param match: mongo search string
@@ -145,12 +141,22 @@ def get_field_average(collection, object_path, match=None):
 
 
 def get_field_execute_operation(operation, collection, object_path, match=None):
-    pipeline = []
-    if match is not None:
-        pipeline.append({'$match': match})
-    pipeline.append({'$group': {'_id': 'null', 'total': {operation: object_path}}})
-    tmp = collection.aggregate(pipeline)
+    pipeline = _build_pipeline(object_path, {'_id': 'null', 'total': {operation: object_path}}, match=match)
+    query = collection.aggregate(pipeline)
     result = 0
-    for item in tmp:
+    for item in query:
         result = item['total']
     return result
+
+
+def _build_pipeline(object_path: str, group: dict, unwind: bool = False, sort_key: Optional[SON] = None,
+                    match: Optional[dict] = None) -> List[dict]:
+    pipeline = []
+    if unwind:
+        pipeline.append({'$unwind': object_path})
+    if match:
+        pipeline.append({'$match': match})
+    pipeline.append({'$group': group})
+    if sort_key:
+        pipeline.append({'$sort': sort_key})
+    return pipeline

tests/test_aggregate.py

-from common_helper_mongo.aggregate import get_objects_and_count_of_occurrence,\
-    get_field_sum, get_field_average, get_list_of_all_values,\
-    get_list_of_all_values_and_collect_information_of_additional_field
+from common_helper_mongo.aggregate import (
+    get_all_value_combinations_of_fields, get_field_average, get_field_sum, get_list_of_all_values,
+    get_objects_and_count_of_occurrence,
+)
 from tests.base_class_database_test import MongoDbTest
 
 
@@ -25,31 +26,40 @@ class TestAggregate(MongoDbTest):
         self.assertEqual(len(result), 4)
         self.assertEqual(result[0], "a")
 
-    def test_get_list_of_all_values_and_collect_information_of_additional_field(self):
+    def test_get_all_value_combinations_of_fields(self):
+        self.test_collection.insert_many([
+            {"test_list": ["a", "b"], "test_value": 1},
+            {"test_list": ["c", "d"], "test_value": 2},
+            {"test_list": ["a", "d"], "test_value": 1}
+        ])
+        result = get_all_value_combinations_of_fields(self.test_collection, "$test_list", "$test_value", unwind=True)
+        assert result == {'a': [1], 'b': [1], 'c': [2], 'd': [1, 2]}
+
+    def test_get_all_value_combinations_of_fields_id(self):
         self.add_list_test_data()
-        result = get_list_of_all_values_and_collect_information_of_additional_field(self.test_collection, "$test_list", "$_id", unwind=True, match=None)
+        result = get_all_value_combinations_of_fields(self.test_collection, "$test_list", "$_id", unwind=True, match=None)
         self.assertIsInstance(result, dict, "result should be a dict")
         self.assertEqual(len(result.keys()), 4, "number of results not correct")
         self.assertEqual(len(result['c']), 2, "c should have two related object ids")
         self.assertEqual(len(result['a']), 1, "a should have one related object id")
 
-    def test_get_objects_and_count_of_occurence(self):
+    def test_get_objects_and_count_of_occurrence(self):
         self.add_simple_test_data()
         result = get_objects_and_count_of_occurrence(self.test_collection, "$test_txt", unwind=False, match=None)
         self.assertEqual(len(result), 10, "number of results not correct")
-        self.assertEqual(result[0]['_id'], "item 1", "should be the fist element because it has two ocurrences")
+        self.assertEqual(result[0]['_id'], "item 1", "should be the fist element because it has two occurrences")
         self.assertEqual(result[0]['count'], 2)
 
     def test_get_objects_and_count_unwind(self):
         self.add_list_test_data()
         result = get_objects_and_count_of_occurrence(self.test_collection, "$test_list", unwind=True, match=None)
         self.assertEqual(len(result), 4, "number of results not correct")
-        self.assertEqual(result[0]['_id'], "c", "should be the first element because it has two ocurrences")
+        self.assertEqual(result[0]['_id'], "c", "should be the first element because it has two occurrences")
         self.assertEqual(result[0]['count'], 2)
 
     def test_get_objects_and_count_match(self):
         self.add_simple_test_data()
-        result = get_objects_and_count_of_occurrence(self.test_collection, "$test_txt", unwind="False", match={"test_int": 0})
+        result = get_objects_and_count_of_occurrence(self.test_collection, "$test_txt", unwind=False, match={"test_int": 0})
         self.assertEqual(len(result), 1, "number of results not correct")
         self.assertEqual(result[0]['_id'], "item 0")