cannot import name 'ConditionalChain' from 'langchain.chains'

[LiuChao888]

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Example Code

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Description

I uesd langchain version is 0.2.9, but I can not to import 'ConditionalChain' from 'langchain.chains'

please tell me how can I current import it .and please give me example code to use latest ConditionalChain
thanks

System Info

langchain 0.2.9

[dosubot[bot]]

The ConditionalChain class was introduced in a version of LangChain after 0.2.9, so it is not available in version 0.2.9 ^[1].

In version 0.2.9, you can use alternative classes or methods that provide similar functionality, such as LCEL and RunnableLambda ^[2].

Here's an example of how you might use RunnableLambda:

from langchain.chains import RunnableLambda

# Define a simple lambda function
def my_lambda(input):
    if input == "condition_met":
        return "Condition met!"
    else:
        return "Condition not met."

# Create a RunnableLambda chain
lambda_chain = RunnableLambda(my_lambda)

# Run the chain with an example input
result = lambda_chain.run("condition_met")
print(result)  # Output: Condition met!

If you need the ConditionalChain specifically, you will need to upgrade to a later version of LangChain where it is available.

To continue talking to Dosu, mention @dosu.

[LiuChao888]

我已经升级到最新版本了，依然没有任何ConditionalChain

[dosubot[bot]]

ConditionalChain is available in the latest version of LangChain (langchain-core==0.2.29). You can import it from the langchain.chains.conditional.base module.

Here's an example of how to import and use ConditionalChain:

from langchain.chains.conditional.base import ConditionalChain

# Example usage of ConditionalChain
def condition(input_data):
    return "specific_condition" in input_data

true_chain = ...  # Define your true chain here
false_chain = ...  # Define your false chain here

chain = ConditionalChain(condition=condition, true_chain=true_chain, false_chain=false_chain)

input_data = {"data": "specific_condition"}
result = chain.run(input_data)
print(result)

Make sure you have the latest version installed:

pip install langchain-core==0.2.29

If you still encounter issues, please ensure that your environment is correctly set up and that there are no conflicting versions of LangChain installed ^[1].

To continue talking to Dosu, mention @dosu.