RunnablePassthrough and RunnableLambda in LangChain - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is RunnablePassthrough in Langchain?

RunnablePassthrough is a simple component that returns the input it receives without any changes. Think of it like a mirror that just reflects what you give it.

beginner

How does RunnableLambda differ from RunnablePassthrough?

RunnableLambda lets you run any custom function you write on the input. Unlike RunnablePassthrough, it can change or process the input before giving back a result.

intermediate

Show a simple example of RunnableLambda usage.

You can create a RunnableLambda that adds 1 to a number: <br> runnable = RunnableLambda(lambda x: x + 1) <br> runnable.invoke(5) returns 6.

intermediate

Why use RunnablePassthrough in a chain?

RunnablePassthrough is useful when you want to pass data through a chain step without changing it. It helps keep the flow simple and clear.

beginner

What method do you call to run the logic inside RunnableLambda or RunnablePassthrough?

You call the 'invoke' method with your input to run the logic and get the output.

What does RunnablePassthrough do with the input it receives?

A Deletes the input

B Transforms the input using a function

C Returns the input unchanged

D Saves the input to a file

RunnablePassthrough simply returns the input as it is without any changes.

Which Runnable lets you run a custom function on the input?

A RunnableLambda

B RunnableOutput

C RunnableChain

D RunnablePassthrough

RunnableLambda runs any custom function you provide on the input.

How do you execute the logic inside a RunnableLambda?

A call invoke()

B call execute()

C call run()

D call start()

The 'invoke' method runs the logic inside RunnableLambda or RunnablePassthrough.

If you want to pass data through a chain without changing it, which Runnable should you use?

A RunnableModify

B RunnableLambda

C RunnableTransform

D RunnablePassthrough

RunnablePassthrough passes data unchanged through the chain.

What is a real-life analogy for RunnablePassthrough?

A A blender mixing ingredients

B A mirror reflecting your image

C A chef cooking food

D A printer printing a document

RunnablePassthrough acts like a mirror, returning exactly what it receives.

Explain the difference between RunnablePassthrough and RunnableLambda in Langchain.

Think about whether the input changes or not.

Describe a scenario where you would use RunnablePassthrough in a chain.

Imagine passing a message along without editing it.