SelectFieldDynamic use function for choices

gistfile1.txt

class SelectFieldDynamic(SelectField):
    # use function in choices
    
    def __init__(self, label=None, validators=None, coerce=str, choices=None, validate_choice=True, **kwargs):
        super(SelectFieldDynamic, self).__init__(label, validators, **kwargs)
        self.coerce = coerce
        self.choices = choices
        self.validate_choice = validate_choice

    def iter_choices(self):
        if not self.choices:
            choices = []
        elif callable(self.choices):
            choices = self.choices()
        elif isinstance(self.choices[0], (list, tuple)):
            choices = self.choices
        else:
            choices = zip(self.choices, self.choices)

        for value, label in choices:
            yield (value, label, self.coerce(value) == self.data)