Understanding String-Based Prompt Templates

At its core, a prompt template is simply a pre-defined structure for the text you send to a large language model (LLM). Among the various types available in frameworks like LangChain, the string-based prompt template is perhaps the most fundamental and intuitive. It represents the prompt as a single continuous string of text, where certain parts are designated as placeholders to be filled in dynamically.

Think of a string-based template as a Mad Libs® game for your LLM. You have a static sentence or paragraph, and you substitute specific words or phrases (the variables) into predetermined slots. LangChain's `PromptTemplate` class is the primary tool for creating and managing these string-based structures.