WTForms populate_obj advantage

populate_obj_in_wtforms.py

##Complex Models:

class Profile(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(100))
    reports = db.relationship(
        'Report', backref='profile_of_report', lazy='dynamic')

class Report(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    profile_id = db.Column(db.Integer, db.ForeignKey(Profile.id))
    disease_name = db.Column(db.String(50))
    reported_date = db.Column(db.DateTime(), default=datetime.now())


##The form:


class ProfileForm(Form):
    name = StringField('Name', validators=[validators.Required()])
    reports = FieldList(FormField(ReportForm), min_entries=2)

class ReportForm(Form):
    disease_name = StringField('Disease Name')
    reported_date = DateField('Reported Date', default=date.today())


##The view:

def profile_page():
    form = ProfileForm()
    if request.method == 'POST':
        if form.validate_on_submit():
            profile = Profile()
            for _ in form.reports #we create the same number of object which we need to populate.
                profile.reports.append(Report())
            form.populate_obj(profile)
            db.session.add(profile)
            db.session.commit()
    return render_template('profile_page.html', form=form)

Thanks. It seems to work fine. Also, Have you tried https://github.com/kvesteri/wtforms-alchemy ?