def __init__(self, package, version):
        """Construct a new requirement.

        :param package: the package name.
        :param version: a semver compatible version specification.
        """
        self.package = package
        self.version = version
        if self.version and not re.match(r"[<=>~]", version[:2]):
            self.version = "=={}".format(self.version)
def image_delete(filename):
    thumbnail_filepath = os.path.join(app.config.get('UPLOAD_FOLDER'), filename)
    filepath = thumbnail_filepath.replace('_thumbnail', '')
    os.remove(filepath)
    os.remove(thumbnail_filepath)