Few-shot prompt templates in LangChain - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the output of this few-shot prompt template code?

Consider this LangChain few-shot prompt template code snippet. What will be the final prompt text after rendering?

LangChain

from langchain.prompts import FewShotPromptTemplate, PromptTemplate

examples = [
    {"input": "Hello", "output": "Hi there!"},
    {"input": "Bye", "output": "Goodbye!"}
]

example_prompt = PromptTemplate(
    input_variables=["input", "output"],
    template="Input: {input}\nResponse: {output}"
)

few_shot = FewShotPromptTemplate(
    examples=examples,
    example_prompt=example_prompt,
    prefix="You are a helpful assistant.",
    suffix="Input: {user_input}\nResponse:",
    input_variables=["user_input"]
)

final_prompt = few_shot.format(user_input="Hello")
print(final_prompt)

A

You are a helpful assistant.
Input: Hello
Response: Hi there!
Input: Bye
Response: Goodbye!
Input: Hello
Response:

B

You are a helpful assistant.
Input: Hello
Response: Hi there!
Input: Bye
Response: Goodbye!
Input: Hello
Response: Hi there!

C

You are a helpful assistant.
Input: Hello
Response: Hi there!
Input: Bye
Response: Goodbye!
Response: Hello
Input:

D

You are a helpful assistant.
Input: Hello
Response: Goodbye!
Input: Bye
Response: Hi there!
Input: Hello
Response:

💡 Hint

Look at how the examples are formatted and how the suffix uses the user input.

The FewShotPromptTemplate inserts all examples formatted by example_prompt between prefix and suffix. The suffix includes the new user input, waiting for the model's response.

📝 Syntax

intermediate

Which option correctly defines a FewShotPromptTemplate with multiple input variables?

You want to create a FewShotPromptTemplate that uses examples with inputs 'question' and 'answer', and a suffix that takes 'new_question'. Which code snippet is correct?

A

FewShotPromptTemplate(
  examples=examples,
  example_prompt=PromptTemplate(input_variables=["question", "answer"], template="Q: {question}\nA: {answer}"),
  prefix="Answer the questions.",
  suffix="Q: {new_question}\nA:",
  input_variables=["answer"]
)

B

FewShotPromptTemplate(
  examples=examples,
  example_prompt=PromptTemplate(input_variables=["question", "answer"], template="Q: {question}\nA: {answer}"),
  prefix="Answer the questions.",
  suffix="Q: {question}\nA:",
  input_variables=["new_question"]
)

C

FewShotPromptTemplate(
  examples=examples,
  example_prompt=PromptTemplate(input_variables=["question", "answer"], template="Q: {question}\nA: {answer}"),
  prefix="Answer the questions.",
  suffix="Q: {new_question}\nA:",
  input_variables=["question"]
)

D

FewShotPromptTemplate(
  examples=examples,
  example_prompt=PromptTemplate(input_variables=["question", "answer"], template="Q: {question}\nA: {answer}"),
  prefix="Answer the questions.",
  suffix="Q: {new_question}\nA:",
  input_variables=["new_question"]
)

💡 Hint

Check that the suffix uses the same variable name as in input_variables.

The suffix uses {new_question}, so input_variables must include 'new_question'. The example_prompt uses 'question' and 'answer' for examples.

🔧 Debug

advanced

What error does this FewShotPromptTemplate code raise?

This code tries to create a FewShotPromptTemplate but fails. What error will it raise?

LangChain

from langchain.prompts import FewShotPromptTemplate, PromptTemplate

examples = [{"input": "Hi", "output": "Hello!"}]

example_prompt = PromptTemplate(
    input_variables=["input", "output"],
    template="Input: {input}\nOutput: {output}"
)

few_shot = FewShotPromptTemplate(
    examples=examples,
    example_prompt=example_prompt,
    prefix="Start conversation.",
    suffix="Input: {user_input}\nOutput:",
    input_variables=["user_input", "extra"]
)

few_shot.format(user_input="Hi")

A No error, outputs the formatted prompt

B KeyError: 'extra'

C ValueError: input_variables contains variables not in suffix or prefix

D TypeError: format() missing 1 required positional argument

💡 Hint

Check which variables are used in suffix and prefix versus input_variables.

The input_variables list includes 'extra' which is not used in prefix or suffix, so when formatting without 'extra', a KeyError occurs.

❓ state_output

advanced

What is the number of example blocks in the rendered prompt?

Given this FewShotPromptTemplate with 3 examples, how many example blocks appear in the final prompt string?

LangChain

examples = [
  {"q": "What is AI?", "a": "Artificial Intelligence."},
  {"q": "What is ML?", "a": "Machine Learning."},
  {"q": "What is NLP?", "a": "Natural Language Processing."}
]

example_prompt = PromptTemplate(
  input_variables=["q", "a"],
  template="Q: {q}\nA: {a}"
)

few_shot = FewShotPromptTemplate(
  examples=examples,
  example_prompt=example_prompt,
  prefix="Answer the following questions.",
  suffix="Q: {new_q}\nA:",
  input_variables=["new_q"]
)

prompt_text = few_shot.format(new_q="What is Python?")

A 4

B 1

C 3

D 0

💡 Hint

Count how many example dictionaries are in the examples list.

The examples list has 3 items, so 3 example blocks appear in the prompt.

🧠 Conceptual

expert

Which statement best describes the role of 'example_prompt' in FewShotPromptTemplate?

In LangChain's FewShotPromptTemplate, what is the main purpose of the 'example_prompt' parameter?

A It defines how each example dictionary is formatted into text before being inserted into the prompt.

B It specifies the variables required by the suffix template for new inputs.

C It controls the order in which examples appear in the final prompt.

D It validates the types of inputs passed to the FewShotPromptTemplate.

💡 Hint

Think about how examples become text in the prompt.

The example_prompt is a PromptTemplate that formats each example dictionary into a text block to be included in the prompt.