Flask API Abort

Introduction

When working with Flask to develop API, sometimes we need to abort the request and return an error message to the user. Flask provides a simple way to accomplish this through the abort() function.

Abort Function

The abort() function is a Flask utility function that raises a HTTPException with the given status code. It takes one argument, which is the status code of the response to be returned.

Here is the syntax:

from flask import abort

abort(status_code)

The status_code is a standard HTTP status code, such as 404 for not found, 401 for unauthorized or 500 for internal server error.

Usage

Here is how we can use abort() function in our Flask API code:

from flask import Flask, abort

app = Flask(__name__)

@app.route('/user/<int:user_id>')
def get_user(user_id):
    user = get_user_by_id(user_id)
    if user is None:
        abort(404)

    return jsonify(user)

In the above code, if the get_user_by_id() function returns None, we'll abort the request and return a 404 status code.

Conclusion

The abort() function is a useful feature in Flask to handle HTTP errors in our API. It provides a simple and effective way to return standard HTTP response codes to the user.