Format template output

The output of the format method is available as a string, list of messages and ChatPromptValue

As string:

output = chat_prompt.format(input_language="English", output_language="French", text="I love programming.")
output

    'System: You are a helpful assistant that translates English to French.\nHuman: I love programming.'

# or alternatively
output_2 = chat_prompt.format_prompt(input_language="English", output_language="French", text="I love programming.").to_string()

assert output == output_2

As list of Message objects:

chat_prompt.format_prompt(input_language="English", output_language="French", text="I love programming.").to_messages()

    [SystemMessage(content='You are a helpful assistant that translates English to French.', additional_kwargs={}),
     HumanMessage(content='I love programming.', additional_kwargs={})]

As ChatPromptValue:

chat_prompt.format_prompt(input_language="English", output_language="French", text="I love programming.")

    ChatPromptValue(messages=[SystemMessage(content='You are a helpful assistant that translates English to French.', additional_kwargs={}), HumanMessage(content='I love programming.', additional_kwargs={})])