Update app.py

app.py

@@ -347,6 +347,11 @@ def parser_node(state: State) -> State:
   '''
   props_string = state["props_string"]
   query_task = state["query_task"]
+  tool_choice = state["tool_choice"]
+
+  if (tool_choice[0] == None) and (tool_choice[1] == None):
+    state["loop_again"] = "finish_gracefully"
+    return state
 
   check_prompt = f'Determine if there is enough CONTEXT below to answer the original \
 QUERY TASK. If there is, respond with "PROCEED #" . If there is not enough information \
@@ -397,6 +402,21 @@ TOOL RESULTS: {props_string}. '
 
   return {"messages": res}
 
+def graceful_exit_node(state: State) -> State:
+  '''
+    Called when the Agent cannot assign any tools for the task
+  '''
+  props_string = state["props_string"]
+  prompt = f'You are a chemistry agent that has not been able to fulfill the task assigned. \
+Write an apology to the user and include any information in the CONTEXT below, just in case it can \
+prove useful. \n \
+CONTEXT: {props_string} \'
+
+  res = chat_model.invoke(prompt)
+
+  return {"messages": res}
+    
+
 def get_chemtool(state):
   '''
   '''
@@ -425,6 +445,8 @@ def loop_or_not(state):
   print(f"(line 417) Loop? {state['loop_again']}")
   if state["loop_again"] == "loop_again":
     return True
+  elif tate["loop_again"] == "finish_gracefully":
+    return 'lets_get_outta_here'
   else:
     return False
 
@@ -446,6 +468,7 @@ builder.add_node("similars_node", similars_node)
 builder.add_node("loop_node", loop_node)
 builder.add_node("parser_node", parser_node)
 builder.add_node("reflect_node", reflect_node)
+builder.add_node("graceful_exit_node", graceful_exit_node)
 
 builder.add_edge(START, "first_node")
 builder.add_conditional_edges("first_node", get_chemtool, {
@@ -473,9 +496,11 @@ builder.add_conditional_edges("loop_node", get_chemtool, {
 
 builder.add_conditional_edges("parser_node", loop_or_not, {
     True: "retry_node",
+    'lets_get_outta_here': "graceful_exit_node",
     False: "reflect_node"})
 
 builder.add_edge("reflect_node", END)
+builder.add_edge("graceful_exit_node", END)
 
 graph = builder.compile()