Added support in recurring group name in files.

c3d/c3d.py

@@ -1084,17 +1084,25 @@ def check_parameters(params):
         else:
             warnings.warn('No analog data found in file.')
 
-    def add_group(self, group_id, name, desc):
+    def add_group(self, group_id, name, desc, rename_duplicated_groups=False):
         '''Add a new parameter group.
 
         Parameters
         ----------
         group_id : int
             The numeric ID for a group to check or create.
-        name : str, optional
+        name : str
             If a group is created, assign this name to the group.
+            The name will be turned to upper case letters.
         desc : str, optional
             If a group is created, assign this description to the group.
+        rename_duplicated_groups : bool
+            If True, when adding a group with a name that already exists, the group will be renamed to 
+            `{name}{group_id}`.
+            The original group will not be renamed.
+            In general, having multiple groups with the same name is against the c3d specification.
+            This option only exists to handle edge cases where files are not created according to the spec and still 
+            need to be imported.
 
         Returns
         -------
@@ -1108,14 +1116,23 @@ def add_group(self, group_id, name, desc):
         '''
         if not is_integer(group_id):
             raise ValueError('Expected Group numerical key to be integer, was %s.' % type(group_id))
-        if not (isinstance(name, str) or name is None):
+        if not isinstance(name, str):
             raise ValueError('Expected Group name key to be string, was %s.' % type(name))
         group_id = int(group_id) # Assert python int
         if group_id in self._groups:
-            raise KeyError(group_id)
+            raise KeyError('Group with numerical key {} already exists'.format(group_id))
         name = name.upper()
         if name in self._groups:
-            raise KeyError(name)
+            if rename_duplicated_groups is True:
+                # In some cases group name is not unique (though c3d spec requires that).
+                # To allow using such files we auto-generate new name.
+                # Notice that referring to this group's parameters later with the original name will fail.
+                new_name = name + str(group_id)
+                warnings.warn(f'Repeated group name {name} modified to {new_name}')
+                name = new_name
+            else:
+                raise KeyError(f'A group with the name {name} already exists.')
+
         group = self._groups[name] = self._groups[group_id] = Group(self._dtypes, name, desc)
         return group
 
@@ -1437,7 +1454,9 @@ def seek_param_section_header():
                     self.rename_group(group, name)
                     group.desc = desc
                 else:
-                    self.add_group(group_id, name, desc)
+                    # We allow duplicated group names here, even though it is against the c3d spec.
+                    # The groups will be renamed.
+                    self.add_group(group_id, name, desc, rename_duplicated_groups=True)
 
         self._check_metadata()
 

test/test_group_accessors.py

@@ -136,6 +136,22 @@ def test_Manager_add_group(self):
         ref.verify_add_group(100)
         ref.verify_remove_all_using_numeric()
 
+    def test_Manager_add_group_duplicated_names(self):
+        '''Check that groups with the same name can be added if the option is enabled.'''
+        reader = c3d.Reader(Zipload._get(self.ZIP, self.INTEL_REAL))
+        ref = GroupSample(reader)
+        test_name = "TEST_NAME"
+        ref.manager.add_group(ref.max_key + 1, test_name, '')
+
+        # Test default
+        with self.assertRaises(KeyError):
+            ref.manager.add_group(ref.max_key + 2, test_name, '')
+
+        # Test with option on
+        new_id = ref.max_key + 2
+        ref.manager.add_group(new_id, test_name, '', rename_duplicated_groups=True)
+        self.assertEqual(ref.manager._groups[new_id].name, test_name.upper() + str(new_id))
+
     def test_Manager_removing_group_from_numeric(self):
         '''Test if removing groups acts as intended.'''
         reader = c3d.Reader(Zipload._get(self.ZIP, self.INTEL_REAL))