flask restful: passing parameters to GET request

Edit: reqparse is no longer the recommended way to do this with flask-restful!, but there is another example using marshmallow below.

The reqparse object is deprecated. See the docs or the second example in this post for alternatives.

Use reqparse. You can see another example in the flask-restful docs.

It performs validation on the parameters and does not require jsonify.

from flask import Flaskfrom flask_restful import Resource, Api, reqparseapp = Flask(__name__)api = Api(app)class BarAPI(Resource):    def get(self):        parser = reqparse.RequestParser()        parser.add_argument('key1', type=str)        parser.add_argument('key2', type=str)        return parser.parse_args()api.add_resource(BarAPI, '/bar', endpoint='bar')if __name__ == '__main__':    app.run(debug=True)

Another way is to use marshmallow.

You can use a Schema class,to validate request.args (for a PUT/POST request you might validate request.form)

from flask import Flask, request, abortfrom flask_restful import Resource, Apifrom marshmallow import Schema, fieldsclass BarQuerySchema(Schema):    key1 = fields.Str(required=True)    key2 = fields.Str(required=True)app = Flask(__name__)api = Api(app)schema = BarQuerySchema()class BarAPI(Resource):    def get(self):        errors = schema.validate(request.args)        if errors:            abort(400, str(errors))        return 'ok'api.add_resource(BarAPI, '/bar', endpoint='bar')# omit of you intend to use `flask run` commandif __name__ == '__main__':    app.run(debug=True)

This example requires that both parameters be present.

Flask can parse arguments through request

from flask import request

You can use following lines in the block that requires GET parameters. GET is declared in @app.route() declaration.

args = request.argsprint (args) # For debuggingno1 = args['key1']no2 = args['key2']return jsonify(dict(data=[no1, no2])) # or whatever is required

Since reqparse is deprecated, here is a solution using the WebArgs library:

from flask import Flaskfrom flask_restful import Api, Resource, abortfrom webargs import fields, validatefrom webargs.flaskparser import use_kwargs, parserapp = Flask(__name__)api = Api(app)class Foo(Resource):    args = {        'bar': fields.Str(            required=True,            validate=validate.OneOf(['baz', 'qux']),        ),    }    @use_kwargs(args)    def get(self, bar):        return {'bar': bar}api.add_resource(Foo, '/foo', endpoint='foo')# This error handler is necessary for usage with Flask-RESTful.@parser.error_handlerdef handle_request_parsing_error(err, req, schema, *, error_status_code, error_headers):    abort(error_status_code, errors=err.messages)if __name__ == '__main__':    app.run(debug=True)

For more examples, see the Flask-RESTful example in the WebArgs repository.