debugpy: Improve variable retrievals.

Signed-off-by: Jos Verlinde <jos_verlinde@hotmail.com>

python-ecosys/debugpy/debugpy/server/debug_session.py

@@ -328,7 +328,10 @@ class DebugSession:
         expression = args.get("expression", "")
         frame_id = args.get("frameId")
         context = args.get("context", "watch")
-        
+        if not expression:
+            self.channel.send_response(CMD_EVALUATE, seq, success=False, 
+                                     message="No expression provided")
+            return
         try:
             result = self.pdb.evaluate_expression(expression, frame_id)
             self.channel.send_response(CMD_EVALUATE, seq, body={

python-ecosys/debugpy/debugpy/server/pdb_adapter.py

@@ -235,7 +235,7 @@ class PdbAdapter:
                 continue
                 
             try:
-                value_str = str(value)
+                value_str = repr(value)
                 type_str = type(value).__name__
                 
                 variables.append({