Error 'Error in StdOutCallbackHandler.on_chain_start callback: AttributeError("'NoneType' object has no attribute 'get'")"

[mraguth]

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Example Code

from langchain_experimental.agents import create_pandas_dataframe_agent
from langchain.agents.agent_types import AgentType
import os
import pandas as pd

agent = create_pandas_dataframe_agent(
    llm,
    df,
    agent_type="openai-tools",
    verbose=True,
    return_intermediate_steps=True,
    allow_dangerous_code=True,
    allow_dangerous_requests=True,
)

Description

While I am running above code, I am getting this error. But I am still getting the desired output. How I fix this? please help.

Error in StdOutCallbackHandler.on_chain_start callback: AttributeError("'NoneType' object has no attribute 'get'")

System Info

Name: langchain
Version: 0.3.0

Name: pydantic
Version: 2.9.2

[dosubot[bot]]

To fix the AttributeError: "'NoneType' object has no attribute 'get'" in the StdOutCallbackHandler.on_chain_start callback, ensure that the inputs parameter passed to on_chain_start is not None. You can provide an empty dictionary as a default value if inputs is None.

Here is the relevant part of the code with the fix:

run_manager = await cm.on_chain_start(
    {"name": group_name}, inputs or {}, run_id=run_id
)

This ensures that if inputs is None, an empty dictionary {} will be used instead, preventing the AttributeError ^[1].

To continue talking to Dosu, mention @dosu.

[mraguth]

@dosu 'NameError: name 'cm' is not defined' Error

[dosubot[bot]]

The NameError: name 'cm' is not defined' error indicates that the variable cm is not defined in your code. The cm variable should be an instance of the CallbackManager class or a similar callback manager.

Here's an example of how you can define and use a CallbackManager:

from langchain.callbacks.manager import CallbackManager
from langchain.callbacks.stdout import StdOutCallbackHandler

# Create an instance of the CallbackManager
cm = CallbackManager(handlers=[StdOutCallbackHandler()])

# Example usage with the on_chain_start method
run_manager = await cm.on_chain_start(
    {"name": "example_chain"}, inputs or {}, run_id=run_id
)

Make sure to replace "example_chain" and run_id with appropriate values for your use case. This should resolve the NameError and ensure that the inputs parameter is handled correctly to avoid the AttributeError ^[1].

To continue talking to Dosu, mention @dosu.

[mraguth]

@dosu found that 'verbose=True,' is causing the error in the query with new pydantic version

[dosubot[bot]]

The verbose=True parameter causing the error with the new Pydantic version suggests that the verbose logging might be interacting poorly with the callback handlers. You can try removing or setting verbose=False to avoid this issue:

agent = create_pandas_dataframe_agent(
    llm,
    df,
    agent_type="openai-tools",
    verbose=False,  # Set verbose to False
    return_intermediate_steps=True,
    allow_dangerous_code=True,
    allow_dangerous_requests=True,
)

This should prevent the AttributeError from occurring. If you still need verbose output, consider implementing custom logging or debugging mechanisms.

To continue talking to Dosu, mention @dosu.

[adobelis]

@dosu: I tried this and it doesn't throw an error, but my callback also doesn't appear to be doing anything.