禁用WTForms SelectField中的某个选项

from flask_wtf import FlaskForm
from wtforms import SelectField

class MyForm(FlaskForm):
    my_select = SelectField('My Select', choices=[('1', 'Option 1'), ('2', 'Option 2'), ('3', 'Option 3')])

# 禁用选项2
form = MyForm()
form.my_select.choices[1] = ('2', '')  # 或者 ('2', None)