Utils: add support for lists in leaves of dict properties paths

utils/dict_property_access.py

 """
-Module with helper functions for accessing dictionary properties
+Module with helper functions for accessing container properties
 """
 
 
-def get_property_value(dictionary, str_property, default_null_value=None):
+def get_property_value(container, str_property, default_null_value=None):
     """
-    :param dictionary: dictionary for which to get the value
+    :param container: container for which to get the value
     :param str_property: string path of the property, e.g  '_metadata.assay_data.assay_subcellular_fraction'
     :param default_null_value: value to return when the value in the dict is None.
      For example, it can return '' if indicated
@@ -17,11 +17,19 @@ def get_property_value(dictionary, str_property, default_null_value=None):
     prop_parts = str_property.split('.')
     current_prop = prop_parts[0]
     if len(prop_parts) > 1:
-        current_obj = dictionary.get(current_prop)
+
+        next_path = '.'.join(prop_parts[1::])
+        current_obj = container.get(current_prop)
         if current_obj is None:
             return default_null_value
-        return get_property_value(current_obj, '.'.join(prop_parts[1::]))
+        return get_property_value(current_obj, next_path)
+
+    # support for paths inside a list
+    is_list = isinstance(container, list)
+    if is_list:
+        return [get_property_value(item, current_prop) for item in container]
 
-    value = dictionary.get(current_prop)
+    # usual paths inside a dict
+    value = container.get(current_prop)
     value = default_null_value if value is None else value
     return value

utils/test/test_dict_property_access.py

+"""
+Module to test the dict property access
+"""
+import unittest
+
+from utils import dict_property_access
+
+
+class TestDictPropertyAccess(unittest.TestCase):
+    """
+    Class to test the property access module
+    """
+
+    def test_gets_simple_property(self):
+        """
+        Tests that it gets a simple property
+        """
+        value_must_be = 'hello'
+        prop_path = 'prop1'
+
+        the_dict = {
+            'prop1': value_must_be
+        }
+
+        value_got = dict_property_access.get_property_value(the_dict, prop_path)
+
+        self.assertEqual(value_must_be, value_got, msg=f'The value of {prop_path} was not obtained correctly!')
+
+    def test_gets_nested_property(self):
+        """
+        Tests that it gets a nested property
+        """
+        value_must_be = 'hello'
+        prop_path = 'prop1.prop2.prop3'
+
+        the_dict = {
+            'prop1': {
+                'prop2': {
+                    'prop3': value_must_be
+                }
+            }
+        }
+
+        value_got = dict_property_access.get_property_value(the_dict, prop_path)
+
+        self.assertEqual(value_must_be, value_got, msg=f'The value of {prop_path} was not obtained correctly!')
+
+    def test_gets_nested_property(self):
+        """
+        Tests that it gets a nested property
+        """
+
+        value_must_be = [1, 2, 3]
+        prop_path = 'prop1.prop2.prop3.prop4'
+
+        the_dict = {
+            'prop1': {
+                'prop2': {
+                    'prop3': [
+                        {'prop4': 1},
+                        {'prop4': 2},
+                        {'prop4': 3}
+                    ]
+
+                }
+            }
+        }
+
+        value_got = dict_property_access.get_property_value(the_dict, prop_path)
+
+        self.assertEqual(value_must_be, value_got, msg=f'The value of {prop_path} was not obtained correctly!')