imd = ImmutableMultiDict([('default', ''), ('required', 'on'), ('name',
    'short_text'), ('name', 'another'), ('submit', 'Submit')])
dict(imd)
{'default': [''], 'submit': ['Submit'], 'required': ['on'], 'name': [
    'short_text', 'another']}
In Flask convert form POST object into a representation suitable for mongodb