Method has_changed

django/forms/fields.py:234–251

Return True if data differs from initial.

(self, initial, data)

        return {}

    def has_changed(self, initial, data):
        """Return True if data differs from initial."""
        # Always return False if the field is disabled since self.bound_data
        # always uses the initial value in this case.
        if self.disabled:
            return False
        try:
            data = self.to_python(data)
            if hasattr(self, "_coerce"):
                return self._coerce(data) != self._coerce(initial)
        except ValidationError:
            return True
        # For purposes of seeing whether something has changed, None is
        # the same as an empty string, if the data or initial value we get
        # is None, replace it with ''.
        initial_value = initial if initial is not None else ""
        data_value = data if data is not None else ""
        return initial_value != data_value

    def get_bound_field(self, form, field_name):
        """