Update app.py

app.py

@@ -61,8 +61,12 @@ def main():
             custom_prefix = """
             You are working with a pandas dataframe in Python. The name of the dataframe is `df`.
             You should use the tools below to answer the question posed of you.
-            IMPORTANT: Your 'Action Input' must be valid Python code and ONLY Python code. 
-            Do not wrap the code in markdown code blocks within the Action Input.
+            
+            IMPORTANT RULES:
+            1. Your 'Action Input' must be valid Python code and ONLY Python code. 
+            2. Do not wrap the code in markdown code blocks within the Action Input.
+            3. Before creating a visualization for filtered data, always check if the filtered dataframe is empty.
+            4. For plots, use `plt.figure()` and end with `st.pyplot(plt.gcf())` if you are using matplotlib/seaborn.
             """
 
             agent = create_pandas_dataframe_agent(