forms.py 文件源码

def validate_file(form, field):
        # File cannot end with a forbidden extension
        filename, file_extension = os.path.splitext(field.data.filename)
        if len(file_extension) > 0:
            forbidden_ext = ForbiddenExtension.query.filter(
                ForbiddenExtension.extension == file_extension[1:]).first()
            if forbidden_ext is not None:
                raise ValidationError('Extension not allowed')
        mimedata = field.data
        mimetype = magic.from_buffer(field.data.read(1024), mime=True)
        # File Pointer returns to beginning
        field.data.seek(0, 0)
        # Check for permitted mimetype
        forbidden_mime = ForbiddenMimeType.query.filter(
            ForbiddenMimeType.mimetype == mimetype).first()
        if forbidden_mime is not None:
            raise ValidationError('File MimeType not allowed')
        extension = mimetypes.guess_extension(mimetype)
        if extension is not None:
            forbidden_real = ForbiddenExtension.query.filter(
                ForbiddenExtension.extension == extension[1:]).first()
            if forbidden_real is not None:
                raise ValidationError('Extension not allowed')