[Python] Django MultipleChoiceField not sending valid data in POST

My django form has a field MultipleChoiceField in with a list of tuples as the options.

choice = forms.MultipleChoiceField(
choices = [("1", "Option 1"), ("2", "Option 2"), ("3", "Option 3")],
label="Choose an option",
widget=forms.Select(),
required=True,
)


This creates the DOM element when it is loaded

<select name="choice" id="id_choice">
<option value="1">Option 1</option>
<option value="2">Option 2</option>
<option value="3">Option 3</option>
</select>


However, when it sends the POST request on the form being submitted, instead of giving a value ("1", "Option 1"), it just sends "1". As such, this triggers a ValidationError in the MultipleChoiceField when it is validated, as it has this function which requires the POST value to be a list or a tuple.

def to_python(self, value):
if not value:
return []
elif not isinstance(value, (list, tuple)):
raise ValidationError(
self.error_messages["invalid_list"], code="invalid_list"
)
return [str(val) for val in value]


Is there any way of setting the POST value of the DOM element so that it sends this tuple?

I tried to change it in the views.py function using field.data, but got This QueryDict instance is immutable

Thanks in advance.

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