Receive 'None' from select field as value in post request

Question

I am new too Flask. I receive 'None' instead of value from select field as response. So will be thankful for help!

Here is my layout:

<form method="post">
    <!-- select -->
    <div class="form-group mt-4">  
      <legend for="Sel">Choose criteria to sort</legend>
      <select class="custom-select" id="Sel" name="sel"> <!-- multiple -->       
        {% for field in form.select %}
          <option value="{{ field }}"></option>    
        {% endfor %}      
      </select>
    </div>
    <!-- submit -->
    {{form.submit(class="btn btn-primary")}}
  </form>

And that`s my view:

from flask import Flask, render_template, request
from wtforms import Form, SelectField, SubmitField


app = Flask(__name__)


sel_choice = [ 
    ('sex', 'gender of the person interviewed '), 
    ('city', 'city where pool took place'),
    ('emotion', 'emotional characteristic of person`s comment'),
    ('month', 'month of poll'),
    ('poll_time', 'poll time')
]

class ChoiceForm(Form):
    select = SelectField(u'Criteria', choices=sel_choice)
    submit = SubmitField(label='apply')

@app.route('/', methods=['POST', 'GET'])
def sel():
    form =  ChoiceForm(request.form)
    if request.method == 'POST':
        print(form.select.data)
    return render_template('forms.html', form=form)

That`s what I receive from server:

• Serving Flask app "test.py" (lazy loading)
• Environment: development
• Debug mode: on
• Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
• Restarting with stat
• Debugger is active!

• Debugger PIN: 231-471-963

  None

  127.0.0.1 - - [17/Oct/2019 13:00:55] "POST / HTTP/1.1" 200 -

Answer 1

Change

print(form.select.data)

to

print(request.form.get('sel'))'