Add some comments

k4FWCore/python/k4FWCore/utils.py

@@ -34,9 +34,11 @@ def check_wrong_imports(code: str) -> None:
         code (str): The code to check for wrong imports.
 
     Raises:
-        R
+        ImportError: If the code contains an import of IOSvc or ApplicationMgr from Configurables.
 
     """
+    # Check first that IOSvc is being used, in that case
+    # Importing either ApplicationMgr or IOSvc from Configurables is not allowed
     iosvc_regex = re.compile(
         r"^\s*from\s+(Configurables|k4FWCore)\s+import\s+\(?.*IOSvc.*\)?", re.MULTILINE
     )

python/k4FWCore/ApplicationMgr.py

@@ -57,11 +57,13 @@ def __init__(self, **kwargs):
                     reader = alg
                 elif isinstance(alg, Writer):
                     writer = alg
+            # Remove "input" when the corresponding property is removed from IOSvc
             if reader is None and (props["input"][0] or props["Input"][0]):
                 reader = Reader("k4FWCore__Reader")
                 add_reader = True
             # It seems for a single string the default without a value is '<no value>'
             # while for a list it's an empty list
+            # Remove "output" when the corresponding property is removed from IOSvc
             if (
                 writer is None
                 and (props["output"][0] and props["output"][0] != "<no value>")