ChatPromptTemplate

ChatPromptTemplate

A specialized template designed for chat or conversational contexts. Typically structures prompts to stimulate a dialogue or interactive session.

ChatPromptTemplate.from_template

from langchain.chat_models import ChatOpenAI 
from langchain.prompts import ChatPromptTemplate
from langchain.schema.output_parser import StrOutputParser
#Initializing model
model = ChatOpenAI()
 
#Defining output parser to interpret model's response as a strong
output_parser = StrOutputParser()
 
#Defining a prompt template for generating a product description from a string of product notes
prompt = ChatPromptTemplate.from_template(
	"Create a lively and engaging product description with emojis based on these notes: \n" "{product_notes}"						  
)
 
chain = prompt | model | output_parser
 
# We can call invoke on the chain itself!
product_desc = chain.invoke({"product_notes": "Multi color affordable mobile covers"})
 
print(product_desc)
#Output: 🌈📱 Introducing our vibrant and pocket-friendly mobile covers! 🎉🤩 🌈🌟 Get ready to add a pop of color to your beloved device with our multi-colored mobile covers! Designed to make heads turn and hearts skip a beat, these cases are a true fashion statement in themselves. 🌈💃

ChatPromptTemplate.from_messages

• used to create a chat prompt template from a list of message tuples. Each tuple contains a role (such as “system” or “user”) and a corresponding message or template
• allows for the creation of dynamic chat prompts where parts of the message can be filled in with user-provided input or other variables

Example

from langchain.prompts import ChatPromptTemplate
 
# Define the system prompt
system_prompt = "You are ChatGPT, a helpful assistant."
 
# Create the chat prompt template
chat_prompt = ChatPromptTemplate.from_messages([
    ("system", system_prompt),
    ("user", "{input}")
])
 
# Example of how to use the template with user input
user_input = "Tell me a joke."
filled_prompt = chat_prompt.format(input=user_input)
 
print(filled_prompt)
# output
# system: You are ChatGPT, a helpful assistant.
# user: Tell me a joke.