added comments

Author: dmalan

src/cs50/sql.py

@@ -1,14 +1,19 @@
 def _enable_logging(f):
+    """Enable logging of SQL statements when Flask is in use."""
+
     import logging
     import functools
 
     @functools.wraps(f)
     def decorator(*args, **kwargs):
+
+        # Infer whether Flask is installed
         try:
             import flask
         except ModuleNotFoundError:
             return f(*args, **kwargs)
 
+        # Enable logging
         disabled = logging.getLogger("cs50").disabled
         if flask.current_app:
             logging.getLogger("cs50").disabled = False