python - WTForms doesn't validate MAC address -

i'm using wtforms' macaddress validator, doesn't recognize valid mac addresses enter. why isn't working?

{'choice': [u'invalid mac address.']} 

class editform(form):     choice = textfield('choice', validators=[datarequired(), macaddress()])  @app.route('/', methods=['get', 'post']) def devicechoice():     form = editform()      if form.validate_on_submit():         print form.choice.data         return redirect(url_for('editdevice'))     else:          print form.errors      return render_template('devicechoice.html', form=form) 

<form action="" method="post">     {{ form.hidden_tag() }}     {{ form.choice() }}     <input type="submit"> </form> 

question has been answered @ketouem, putting ":" after every 2 characters of mac address validates form. (12:34:56:78:ab:cd)