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 uninstall_plugin(plugin):
    plugin = get_plugin_from_all(plugin)
    if plugin.uninstallable:
        plugin.uninstall()
        Setting.invalidate_cache()

        flash(_("Plugin has been uninstalled."), "success")
    else:
        flash(_("Cannot uninstall plugin."), "danger")

    return redirect(url_for("management.plugins"))