def clean_username(self):
        username = self.cleaned_data.get('username').split('@')[0]
        if not username:
            raise forms.ValidationError(_('Invalid username provided'))
        return username
Write the blob of each part in *parts* to the package, along with a
dataset/ETHPy150Open jbittel/django-mama-cas/mama_cas/forms.py/LoginFormEmail.clean_username--crossover with--dataset/ETHPy150Open scanny/python-pptx/pptx/opc/pkgwriter.py/PackageWriter._write_parts