Langchain custom tool - passing DataFrame as function parameter

[soumalya2007]

Hi,
I have an user defined function where DataFrame is being passed as parameters. If I need to call this in a custom tool , what will be the way?
Can you cite an example?

[dosubot[bot]]

🤖

Hey @soumalya2007! Nice to see you around again. Looks like you're diving deep into LangChain, that's awesome!

In LangChain, you can pass a DataFrame as a parameter to a user-defined function within a custom tool by using the PythonAstREPLTool class. This class allows you to define local variables that can be used within the tool.

Here is an example of how you can do this:

from langchain.tools import BaseTool
from langchain_experimental.tools.python.tool import PythonAstREPLTool
import pandas as pd

# Define your DataFrame
df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]})

# Define your custom tool with the DataFrame as a local variable
custom_tool = PythonAstREPLTool(locals={"df": df})

# Now, you can use 'df' within your custom tool

In the provided context, you can see this being done in the _get_single_prompt and _get_multi_prompt functions. For example, in the _get_single_prompt function, a PythonAstREPLTool is created with a DataFrame as a local variable:

tools = [PythonAstREPLTool(locals={"df": df})] + list(extra_tools)

In this line, df is the DataFrame that is being passed as a parameter to the function, and it is being set as a local variable within the PythonAstREPLTool. This means that df can now be used within this tool.

You can find more details about the PythonAstREPLTool class in the LangChain repository.

Sources

• libs/experimental/langchain_experimental/agents/agent_toolkits/pandas/base.py
• libs/experimental/langchain_experimental/tools/python/tool.py

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[soumalya2007]

Follow Up question: How 'df' can be used in the other custom tools? Say for an example , I have a function where df is present as one of the parameters. Wnat to make a tool using this function.

[sumitthokar]

hey @soumalya2007, I am working on similar problem. Did you find the solution?

[CrasCris]

Did you find something ?