python - SQLalchemy/wtforms update issue - 400 bad request -

what i'm trying is, once user submits results want update fixture_prediction model according filters. although 400 bad request. log doesnt tell me enough know whats going wrong. ideas?

i think tuple data submitted through form...

the form displays fine when submit form goes straight bad request.

my error

bad request  browser (or proxy) sent request server not understand. 

what have currently:

views

@app.route('/predictor/',methods=['get','post']) @login_required def predictions():     user_id = g.user.id     # retrieve predictions     prediction= db.session.query(fixture_prediction,\                 fixture_prediction.fixture_id,fixture.stage,\                 fixture.home_team,fixture_prediction.home_score,\                 fixture_prediction.away_score,fixture.away_team)\                 .outerjoin(fixture,fixture.id==fixture_prediction.fixture_id)\                 .outerjoin(user,fixture_prediction.user_id == user.id)\                 .filter(fixture_prediction.fixture_id==fixture.id)\                 .filter(fixture_prediction.user_id==user_id).all()     data = {'predictions': prediction}     form = predictionlistform(data=multidict(data))     if request.method == 'post':         if form.validate() == false:             flash('a score missing, please fill in predictions')             render_template('predictor.html', form=form)         else:             #for pred in prediction:             store=fixture_prediction.query\                             .filter_by(user_id=user_id)\                             .filter_by(fixture_id=request.form['fixture_id'])\                             .update({'home_score':request.form['home_score']\                                     ,'away_score':request.form['away_score']})             db.session.commit()             flash('prediction added')             return redirect(url_for("predictions"))     # display current predictions     elif request.method == 'get':         return render_template('predictor.html', form=form) 

template

{% extends "base.html" %}  {% block content %}    <h1>predictions</h1>   <p></p>   <p>please make predictions here</p>   <form action='' method='post'>     {{form.predictions()}}     <p><input type="submit" value="submit predictions"></p>    </form>  {% endblock %} 

forms

class predictionform(wtform):     fixture_id = fields.integerfield(validators=[validators.required()])     stage = fields.textfield(validators=[validators.required()])     home_team = fields.textfield(validators=[validators.required()])     home_score = fields.integerfield(validators=[validators.required()])     away_score = fields.integerfield(validators=[validators.required()])     away_team = fields.textfield(validators=[validators.required()])  class predictionlistform(wtform):     predictions = fieldlist(formfield(predictionform)) 

the problem there no field fixture_id in request.form. results in keyerror being raised underlying multidict, translated 400 flask.

the reason there no fixture_id because using field enclosures fieldlist , formfield both of alter names provide wtforms avoid collisions.

the fix use form instance have access data (as wtforms has mapped you):

# in else clause prediction in form.predictions:     store = fixture_prediction.query \                               .filter_by(user_id=user_id) \                               .filter_by(fixture_id=prediction.fixture_id.data)     # etc.