ChatPromptTemplate for conversations in LangChain - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the ChatPromptTemplate class from langchain.prompts.

LangChain

from langchain.prompts import [1]

Drag options to blanks, or click blank then click option'

AConversationTemplate

BChatPromptTemplate

CPromptTemplate

DChatTemplate

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'PromptTemplate' instead of 'ChatPromptTemplate'.

Trying to import from the wrong module.

The class ChatPromptTemplate is imported from langchain.prompts to create chat prompt templates.

2fill in blank

medium

Complete the code to create a ChatPromptTemplate with a system message and a human message.

LangChain

from langchain.prompts import ChatPromptTemplate, SystemMessagePromptTemplate, HumanMessagePromptTemplate

prompt = ChatPromptTemplate.from_messages([
    SystemMessagePromptTemplate.from_template("You are a helpful assistant."),
    [1].from_template("Hello, how can I help you?")
])

Drag options to blanks, or click blank then click option'

AAssistantMessagePromptTemplate

BUserMessagePromptTemplate

CHumanMessagePromptTemplate

DMessagePromptTemplate

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'UserMessagePromptTemplate' which does not exist.

Using 'AssistantMessagePromptTemplate' for human input.

The human message part of the conversation uses HumanMessagePromptTemplate to define the user's input.

3fill in blank

hard

Fix the error in the code by completing the method to format messages with input variables.

LangChain

response = prompt.format_messages([1]="What is the weather today?")

Drag options to blanks, or click blank then click option'

Ainput

Bquery

Cquestion

Dmessage

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'question' or 'query' which are not defined in the template.

Using 'message' which is not the expected variable name.

The input variable name used in the prompt template is usually input to pass user text.

4fill in blank

hard

Fill both blanks to create a ChatPromptTemplate with system and human messages using templates.

LangChain

prompt = ChatPromptTemplate.from_messages([
    [1].from_template("You are an expert."),
    [2].from_template("Tell me about {{input}}.")
])

Drag options to blanks, or click blank then click option'

ASystemMessagePromptTemplate

BUserMessagePromptTemplate

CHumanMessagePromptTemplate

DAssistantMessagePromptTemplate

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'UserMessagePromptTemplate' which is not valid.

Mixing up system and human message classes.

The system message uses SystemMessagePromptTemplate and the human message uses HumanMessagePromptTemplate.

5fill in blank

hard

Fill all three blanks to create a ChatPromptTemplate with system, human, and AI messages.

LangChain

prompt = ChatPromptTemplate.from_messages([
    [1].from_template("You are a helpful assistant."),
    [2].from_template("What is the capital of France?"),
    [3].from_template("Paris is the capital of France.")
])

Drag options to blanks, or click blank then click option'

ASystemMessagePromptTemplate

BHumanMessagePromptTemplate

CAIMessagePromptTemplate

DAssistantMessagePromptTemplate

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'AssistantMessagePromptTemplate' instead of 'AIMessagePromptTemplate'.

Mixing up human and AI message classes.

The system message uses SystemMessagePromptTemplate, the human message uses HumanMessagePromptTemplate, and the AI message uses AIMessagePromptTemplate.

Practice

1. What is the main purpose of ChatPromptTemplate in Langchain conversations?

easy

A. To organize chat messages with placeholders for dynamic inputs

B. To execute database queries automatically

C. To style chat messages with CSS

D. To store user credentials securely

Solution

1. Step 1: Understand ChatPromptTemplate role

   ChatPromptTemplate helps structure chat messages and insert dynamic user inputs using placeholders.

2. Step 2: Eliminate unrelated options

   Options about database queries, styling, or security are unrelated to ChatPromptTemplate's purpose.

3. Final Answer:

   To organize chat messages with placeholders for dynamic inputs -> Option A

4. Quick Check:

   ChatPromptTemplate = Organize messages + placeholders [OK]

Hint: ChatPromptTemplate structures chat with placeholders [OK]

Common Mistakes:

• Confusing ChatPromptTemplate with styling or security features
• Thinking it runs queries or handles authentication

2. Which of the following is the correct way to create a ChatPromptTemplate with a user input placeholder named 'name'?

easy

A. ChatPromptTemplate.from_template('Hello {name}!')

B. ChatPromptTemplate('Hello $name!')

C. ChatPromptTemplate.create('Hello {{name}}!')

D. ChatPromptTemplate.new('Hello %name%!')

Solution

1. Step 1: Recall correct placeholder syntax

   Langchain uses curly braces {name} inside from_template method to define placeholders.

2. Step 2: Check method and syntax correctness

   Only ChatPromptTemplate.from_template('Hello {name}!') uses from_template and correct {name} placeholder syntax.

3. Final Answer:

   ChatPromptTemplate.from_template('Hello {name}!') -> Option A

4. Quick Check:

   Use from_template with {placeholder} [OK]

Hint: Use from_template and {placeholder} syntax [OK]

Common Mistakes:

• Using wrong placeholder symbols like $ or % or double braces
• Using non-existent methods like create or new

3. Given this code snippet:

from langchain.prompts import ChatPromptTemplate

prompt = ChatPromptTemplate.from_template('Hi {user}! How can I help you today?')
message = prompt.format_prompt(user='Alice').to_messages()
print(message[0].content)

What will be printed?

medium

A. Hi {user}! How can I help you today?

B. Hi Alice! How can I help you today?

C. Hi ! How can I help you today?

D. Error: format_prompt missing argument

Solution

1. Step 1: Understand placeholder replacement

   The placeholder {user} is replaced by the value 'Alice' passed to format_prompt.

2. Step 2: Check printed message content

   message[0].content contains the formatted string with 'Alice' inserted.

3. Final Answer:

   Hi Alice! How can I help you today? -> Option B

4. Quick Check:

   Placeholder replaced with 'Alice' in output [OK]

Hint: format_prompt replaces placeholders with given values [OK]

Common Mistakes:

• Thinking placeholders remain unreplaced in output
• Assuming missing argument error without passing user
• Confusing message object with string directly

4. What is wrong with this code snippet?

from langchain.prompts import ChatPromptTemplate

prompt = ChatPromptTemplate.from_template('Hello {name}!')
message = prompt.format_prompt().to_messages()

medium

A. Placeholder syntax should use $name instead of {name}

B. Incorrect method name 'from_template'

C. Missing argument for placeholder 'name' in format_prompt

D. to_messages() is not a valid method

Solution

1. Step 1: Identify placeholder usage

   The template has a placeholder {name} that requires a value when formatting.

2. Step 2: Check format_prompt call

   format_prompt() is called without providing the required 'name' argument, causing an error.

3. Final Answer:

   Missing argument for placeholder 'name' in format_prompt -> Option C

4. Quick Check:

   Placeholder needs matching argument in format_prompt [OK]

Hint: Always pass all placeholders to format_prompt [OK]

Common Mistakes:

• Forgetting to pass required placeholder arguments
• Thinking method names or syntax are incorrect
• Assuming to_messages() doesn't exist

5. You want to create a conversation prompt that greets the user by name and asks their favorite color, then stores both inputs dynamically. Which approach using ChatPromptTemplate is correct?

hard

A. Use a template 'Hello {name}! What is your favorite color?' and call format_prompt(name='Bob') only

B. Use two separate ChatPromptTemplates, one for name and one for color, then combine messages manually

C. Use a template 'Hello $name, favorite color $color?' and call format_prompt(name='Bob', color='blue')

D. Use a template like 'Hello {name}, what is your favorite color {color}?' and call format_prompt(name='Bob', color='blue')

Solution

1. Step 1: Understand placeholder usage for multiple inputs

   ChatPromptTemplate supports multiple placeholders in one template string, e.g., {name} and {color}.

2. Step 2: Check correct syntax and method usage

   Use a template like 'Hello {name}, what is your favorite color {color}?' and call format_prompt(name='Bob', color='blue') uses correct curly brace placeholders and passes both arguments in format_prompt.

3. Step 3: Evaluate other options

   Use two separate ChatPromptTemplates, one for name and one for color, then combine messages manually is more complex than needed; Use a template 'Hello {name}! What is your favorite color?' and call format_prompt(name='Bob') only misses the color input; Use a template 'Hello $name, favorite color $color?' and call format_prompt(name='Bob', color='blue') uses wrong placeholder syntax.

4. Final Answer:

   Use a template like 'Hello {name}, what is your favorite color {color}?' and call format_prompt(name='Bob', color='blue') -> Option D

5. Quick Check:

   Multiple placeholders with format_prompt arguments [OK]

Hint: Use {placeholder} for each input and pass all in format_prompt [OK]

Common Mistakes:

• Using wrong placeholder syntax like $name
• Splitting conversation unnecessarily into multiple templates
• Not passing all required inputs to format_prompt