Fastapi Tutorial For Beginners: Dynamic Routing Query Parameters: Filtering & Search Logic (Part 3)

Description

Learn how to handle user input like a pro in Part 3 of the FastAPI Masterclass. While path parameters identify a resource, Query Parameters allow your users to sort, filter, and search through data. We will cover how to make parameters optional, set smart defaults, and use FastAPI's powerful validation to keep your backend secure and efficient. [What You’ll Learn] The Query Syntax: How FastAPI automatically detects parameters not in the path. Optional vs. Required: Handling None and default values. Query Validation: Using the Query class for regex, min/max length, and metadata. List Parameters: How to accept multiple values for a single query key. [Timestamps] 0:00 - Path vs. Query: When to use which? 3:10 - Defining your first Query Parameter 7:45 - Making Parameters Optional with Optional or | None 12:20 - Adding Constraints (Length, Regex, and Titles) 18:50 - Handling Lists/Arrays in URL queries 23:15 - The Power Move: The "Ellipsis" (...) for Required Queries FastAPI Tutorial For Beginners, FastAPI Query Parameters, FastAPI Tutorial Part 3, Python API Search, Optional Parameters FastAPI, Python Web Development, Data Filtering Algorithms, E-commerce Backend Design, SaaS API Development, Full Stack Python 2026, Advanced REST API Patterns, Web Search Architecture, API Performance Tuning