__init__.py 文件源码

def __call__(self, fileobj):
        detected_type = magic.from_buffer(fileobj.read(READ_SIZE), mime=True)
        root, extension = os.path.splitext(fileobj.name.lower())

        # seek back to start so a valid file could be read
        # later without resetting the position
        fileobj.seek(0)

        # some versions of libmagic do not report proper mimes for Office subtypes
        # use detection details to transform it to proper mime
        if detected_type in ('application/octet-stream', 'application/vnd.ms-office'):
            detected_type = self.check_word_or_excel(fileobj, detected_type, extension)

        if detected_type not in self.allowed_mimes:
            # use more readable file type names for feedback message
            allowed_types = map(lambda mime_type: mime_type.split('/')[1], self.allowed_mimes)

            raise ValidationError(
                message=self.type_message,
                params={
                    'detected_type': detected_type,
                    'allowed_types': ', '.join(allowed_types)
                },
                code='invalid_type'
            )

        if self.allowed_exts and (extension not in self.allowed_exts):
            raise ValidationError(
                message=self.extension_message,
                params={
                    'extension': extension,
                    'allowed_extensions': ', '.join(self.allowed_exts)
                },
                code='invalid_extension'
            )