Flask API Development: JSON Data Return and Status Code Setting

This article introduces the basic points of returning JSON and setting HTTP status codes when developing APIs with Flask. To return JSON, use the `jsonify` function instead of directly returning a Python dictionary (though this is technically possible, it is not recommended because `jsonify` is more explicit and supports complex data types). `jsonify` automatically sets the `Content-Type: application/json` header. HTTP status codes are used to indicate the result of a request. Common codes include 200 (success), 201 (resource created successfully), 400 (bad request/parameter error), 404 (resource not found), and 500 (server error). Status codes can be set by returning a tuple (`(jsonify(data), status_code)`) or by constructing a response object using `make_response`. Examples cover common scenarios: returning 200 for successful GET requests, 201 for resource creation via POST, 400 for parameter errors, 404 for non-existent resources, and 500 for server errors. Mastering these basics will help standardize Flask API development and enable smooth front-end and back-end data interaction.