[Solved] What is the issue with this Langchain prompt template code?template = PromptTemplate(template="Good morning, {name}", input_variables=["user"]) prompt = template.format(name="John") | LangChain

LangChain - Prompt Templates

What is the issue with this Langchain prompt template code?

template = PromptTemplate(template="Good morning, {name}", input_variables=["user"])
prompt = template.format(name="John")

AThe input_variables list does not include 'name', causing a mismatch.

BThe template string is missing curly braces around 'name'.

CThe format method is called with an undefined variable 'user'.

DThere is no issue; the code will run correctly.

Step-by-Step Solution

Solution:

Step 1: Check input_variables list
The input_variables list must include all placeholders used in the template string.
Step 2: Compare placeholders and input_variables
The template uses {name}, but input_variables contains "user" only, causing a mismatch.
Step 3: Understand format call
The format method uses name="John", which is not declared in input_variables, leading to an error.
Final Answer:
The input_variables list does not include 'name', causing a mismatch. -> Option A
Quick Check:
Placeholder names must match input_variables exactly [OK]

Quick Trick: Input variables must match all placeholders exactly [OK]

Common Mistakes:

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