Python：选择字段"Not a valid choice"

Question

form.py

class Confirm(CSRFForm):
    monitor_updates = SelectField(
        lazy_gettext("Monitor updates of an app"),
        validators=[validators.Optional()], choices=[], coerce=int
    )

view.py

def upload_confirm():
    form = Confirm()

    if form.validate_on_submit:
        if form.monitor_updates.data == 0:
            current_workflow.installation_source.monitor_updates_id = None
            db.session.commit()
        else:
            current_workflow.installation_source.monitor_updates_id = form.monitor_updates.data
            db.session.commit()

    choices = [(app[1][0], app[1][1]) for app in list_choices]
    form.monitor_updates.choices =[(0, "Nothing matches")]
    form.monitor_updates.choices += choices

models.py

class InstallationSource(db.Model):

    monitor_updates_id = db.Column(db.Integer, db.ForeignKey('updates_software.id'))

当填写表格并在下拉列表中 selecting "Nothing matches" 值为 0 时，出现错误。

如果你select一个不同的值，保存是正确的。我只能用数字0，因为其他数字都可以被占用

Answer 1

你需要选择的逻辑

    choices = [(app[1][0], app[1][1]) for app in list_choices]
    form.monitor_updates.choices =[(0, "Nothing matches")]
    form.monitor_updates.choices += choices

在 form.validate_on_submit() 方法之前：

def upload_confirm():
    form = Confirm()

    choices = [(app[1][0], app[1][1]) for app in list_choices]
    form.monitor_updates.choices =[(0, "Nothing matches")]
    form.monitor_updates.choices += choices

    if form.validate_on_submit():
        if form.monitor_updates.data == 0:
            current_workflow.installation_source.monitor_updates_id = None
            db.session.commit()
        else:
            current_workflow.installation_source.monitor_updates_id = form.monitor_updates.data
            db.session.commit()

Python：选择字段"Not a valid choice"

Python: SelectField "Not a valid choice"

python

flask

wtforms

flask-wtforms