forms.py 文件源码

def save(self) -> None:
        """
        Saves all changed values to the database.
        """
        for name, field in self.fields.items():
            value = self.cleaned_data[name]
            if isinstance(value, UploadedFile):
                # Delete old file
                fname = self._s.get(name, as_type=File)
                if fname:
                    try:
                        default_storage.delete(fname.name)
                    except OSError:  # pragma: no cover
                        logger.error('Deleting file %s failed.' % fname.name)

                # Create new file
                newname = default_storage.save(self.get_new_filename(value.name), value)
                value._name = newname
                self._s.set(name, value)
            elif isinstance(value, File):
                # file is unchanged
                continue
            elif isinstance(field, forms.FileField):
                # file is deleted
                fname = self._s.get(name, as_type=File)
                if fname:
                    try:
                        default_storage.delete(fname.name)
                    except OSError:  # pragma: no cover
                        logger.error('Deleting file %s failed.' % fname.name)
                del self._s[name]
            elif value is None:
                del self._s[name]
            elif self._s.get(name, as_type=type(value)) != value:
                self._s.set(name, value)