使用Python webargs分析和输出时出错

Question

webargs能否处理负载中JSON代码中的错误并打印自定义错误消息，而不是默认的400？在

from flask import Flask
from flask import request
from webargs import Arg
from webargs.flaskparser import FlaskParser

parser = FlaskParser()

app = Flask(__name__)

tracks_args = {
    'event': Arg(str, target='querystring'),
    'origin': Arg(str, validate=lambda w: w in ['suggest'], target='json', error='Invalid choice for     origin')
}

@app.route('/tracks/<string:event>', methods=['post'])
def post(event):
    args = parser.parse(tracks_args, request)
    print args
    print event

    return "OK"


if __name__ == '__main__':
    app.run(debug=True, port=8001)

正确的有效载荷应该是

^{pr2}$

如果有一个不正确的，那么应该打印错误消息，应该是

{
   "suggestafasfaesfasef":"test"
}