Add Langchain Pandas DataFrame Agent

docs/examples/langchain/langchain_chat_pandas_df.py

@@ -0,0 +1,176 @@
+"""
+Demonstrates how to use the `ChatInterface` and `PanelCallbackHandler` to create a
+chatbot to talk to your Pandas DataFrame. This is heavily inspired by the 
+[LangChain `chat_pandas_df` Reference Example](https://github.com/langchain-ai/streamlit-agent/blob/main/streamlit_agent/chat_pandas_df.py).
+"""
+from __future__ import annotations
+
+import pandas as pd
+import panel as pn
+import param
+from langchain.agents import AgentType, create_pandas_dataframe_agent
+from langchain.chat_models import ChatOpenAI
+
+from panel_chat_examples import EnvironmentWidgetBase
+
+pn.extension("perspective", design="material")
+
+PENGUINS_URL = (
+    "https://raw.githubusercontent.com/mwaskom/seaborn-data/master/penguins.csv"
+)
+
+
+class Environment(EnvironmentWidgetBase):
+    """Will be asking the user for the API Key if not set as environment variable"""
+
+    OPENAI_API_KEY = param.String()
+
+
+class AgentConfig(param.Parameterized):
+    """Configuration used for the Pandas Agent"""
+
+    user = "Pandas Agent"
+    avatar = "🐼"
+
+    show_chain_of_thought = param.Boolean(default=False)
+
+    def _get_agent_message(self, message: str) -> pn.chat.ChatMessage:
+        return pn.chat.ChatMessage(message, user=self.user, avatar=self.avatar)
+
+
+class AppState(param.Parameterized):
+    data = param.DataFrame()
+
+    llm = param.Parameter(constant=True)
+    pandas_df_agent = param.Parameter(constant=True)
+
+    config: AgentConfig = param.ClassSelector(class_=AgentConfig)
+    environ: Environment = param.ClassSelector(class_=Environment, constant=True)
+
+    def __init__(
+        self, config: AgentConfig | None = None, environ: Environment | None = None
+    ):
+        if not config:
+            config = AgentConfig()
+        if not environ:
+            environ = Environment()
+        super().__init__(config=config, environ=environ)
+
+    @param.depends("environ.OPENAI_API_KEY", on_init=True, watch=True)
+    def _reset_llm(self):
+        with param.edit_constant(self):
+            if self.environ.OPENAI_API_KEY:
+                self.llm = ChatOpenAI(
+                    temperature=0,
+                    model="gpt-3.5-turbo-0613",
+                    api_key=self.environ.OPENAI_API_KEY,
+                    streaming=True,
+                )
+            else:
+                self.llm = None
+
+    @param.depends("llm", "data", on_init=True, watch=True)
+    def _reset_pandas_df_agent(self):
+        with param.edit_constant(self):
+            if not self.error_message:
+                self.pandas_df_agent = create_pandas_dataframe_agent(
+                    self.llm,
+                    self.data,
+                    verbose=True,
+                    agent_type=AgentType.OPENAI_FUNCTIONS,
+                    handle_parsing_errors=True,
+                )
+            else:
+                self.pandas_df_agent = None
+
+    @property
+    def error_message(self):
+        if not self.llm and self.data is None:
+            return """Please provide your `OPENAI_API_KEY`, **upload a `.csv` file** 
+and click the **send** button."""
+        if not self.llm:
+            return "Please provide your `OPENAI_API_KEY`."
+        if self.data is None:
+            return "Please **upload a `.csv` file** and click the **send** button."
+        return ""
+
+    @property
+    def welcome_message(self):
+        text = (
+            f"""I'm your <a href="\
+https://python.langchain.com/docs/integrations/toolkits/pandas" target="_blank">\
+LangChain Pandas DataFrame Agent</a>.
+
+I execute LLM generated Python code under the hood - this can be bad if the `llm`
+generated Python code is harmful. Use cautiously!
+
+{self.error_message}"""
+        ).strip()
+        if self.data is None:
+            text += f"""
+
+Example: <a href="{PENGUINS_URL}" download>penguins.csv<a>
+"""
+        return text
+
+    async def callback(self, contents, user, instance):
+        if isinstance(contents, pd.DataFrame):
+            self.data = contents
+            instance.active = 1
+            message = self.config._get_agent_message(
+                """You can ask me anything about the data. For example 'how many
+species are there?'"""
+            )
+            # We `send` instead of just `return` due to the bug
+            # https://github.com/holoviz/panel/issues/5708
+            instance.send(message, respond=False)
+            return  # message
+
+        if self.error_message:
+            message = self.config._get_agent_message(self.error_message)
+            instance.send(message, respond=False)
+            return  # message
+
+        if self.config.show_chain_of_thought:
+            langchain_callbacks = [
+                pn.chat.langchain.PanelCallbackHandler(instance=instance)
+            ]
+        else:
+            langchain_callbacks = []
+        response = await state.pandas_df_agent.arun(
+            contents, callbacks=langchain_callbacks
+        )
+        message = self.config._get_agent_message(response)
+        instance.send(message, respond=False)
+        return
+
+
+state = AppState()
+
+chat_interface = pn.chat.ChatInterface(
+    widgets=[
+        pn.widgets.FileInput(name="Upload"),
+        pn.widgets.TextInput(name="Message", placeholder="Send a message"),
+    ],
+    renderers=pn.pane.Perspective,
+    callback=state.callback,
+    callback_exception="verbose",
+    show_rerun=False,
+    show_undo=False,
+    show_clear=False,
+    min_height=400,
+)
+chat_interface.send(
+    state.welcome_message, user="Pandas Agent", avatar="🐼", respond=False
+)
+
+layout = pn.template.MaterialTemplate(
+    title="🦜 LangChain - Chat with Pandas DataFrame",
+    main=[chat_interface],
+    sidebar=["Agent Settings", state.config.param.show_chain_of_thought],
+)
+
+if state.environ.variables_not_set:
+    layout.sidebar.append(state.environ)
+
+layout.servable()

pyproject.toml

@@ -91,6 +91,7 @@ dependencies = [
     "openai",
     "panel @ git+https://github.com/holoviz/panel.git@main",
     "pypdf",
+    "tabulate",
     "tiktoken",
 ]