golden hour

/usr/lib/python3/dist-packages/DistUpgrade

File/Folder	Size	Actions
DistUpgradeApport.py	4.95 KB
DistUpgradeAptCdrom.py	12.39 KB
DistUpgradeCache.py	52.93 KB
DistUpgradeConfigParser.py	3.75 KB
DistUpgradeController.py	101.89 KB
DistUpgradeFetcher.py	5.87 KB
DistUpgradeFetcherCore.py	11.2 KB
DistUpgradeFetcherKDE.py	9.72 KB
DistUpgradeFetcherSelf.py	2.02 KB
DistUpgradeGettext.py	2.97 KB
DistUpgradeMain.py	9.1 KB
DistUpgradePatcher.py	3.92 KB
DistUpgradeQuirks.py	49.04 KB
DistUpgradeVersion.py	21 B
DistUpgradeView.py	16.43 KB
DistUpgradeViewGtk3.py	33.85 KB
DistUpgradeViewKDE.py	42.11 KB
DistUpgradeViewNonInteractive.py	13.54 KB
DistUpgradeViewText.py	12.53 KB
GtkProgress.py	3.93 KB
MetaRelease.py	17.06 KB
QUrlOpener.py	3.24 KB
ReleaseNotesViewer.py	7.48 KB
ReleaseNotesViewerWebkit.py	2.91 KB
SimpleGtk3builderApp.py	2.01 KB
SimpleGtkbuilderApp.py	1.99 KB
__init__.py	0 B
__pycache__	-
apt_btrfs_snapshot.py	9.64 KB
apt_clone.py	32.81 KB
dist-upgrade.py	129 B
distro.py	23.15 KB
telemetry.py	3.4 KB
utils.py	17.92 KB
xorg_fix_proprietary.py	3.99 KB

Edit: QUrlOpener.py

# QUrlOpener.py
# -*- Mode: Python; indent-tabs-mode: nil; tab-width: 4; coding: utf-8 -*-
#
#  Copyright (c) 2014-2018 Harald Sitter <apachelogger@kubuntu.org>
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License as
#  published by the Free Software Foundation; either version 2 of the
#  License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program.  If not, see <http://www.gnu.org/licenses/>.

try:
    # 14.04 has a broken pyqt5, so don't even try to import it and require
    # pyqt4.
    # In 14.04 various signals in pyqt5 can not be connected because it thinks
    # the signal does not exist or has an incompatible signature. Since this
    # potentially renders the GUI entirely broken and pyqt5 was not actively
    # used back then it is fair to simply require qt4 on trusty systems.
    from .utils import get_dist
    if get_dist() == 'trusty':
        raise ImportError

from PyQt5.QtCore import QObject, QCoreApplication, pyqtSlot, QUrl
    from PyQt5.QtGui import QDesktopServices
except ImportError:
    from PyQt4.QtCore import QObject, QCoreApplication, pyqtSlot, QUrl
    from PyQt4.QtGui import QDesktopServices

import os
import subprocess

def singleton(class_):
    instances = {}

def instance(*args, **kwargs):
        if class_ not in instances:
            instances[class_] = class_(*args, **kwargs)
        return instances[class_]
    return instance

@singleton
class QUrlOpener(QObject):
    def __init__(self):
        QObject.__init__(self)
        self.setParent(QCoreApplication.instance())

def setupUrlHandles(self):
        # Make sure we don't run a root browser.
        # NOTE: Qt native API can set an openUrl handler from a QObject
        # function, pyqt in theory also allows an arbitrary callable. Latter
        # has been observed to be non-functional so rely on the native handling
        QDesktopServices.setUrlHandler('http', self, 'openUrl')
        QDesktopServices.setUrlHandler('https', self, 'openUrl')

# NOTE: largely code copy from ReleaseNotesViewer which imports GTK.
    @pyqtSlot(QUrl)
    def openUrl(self, url):
        url = url.toString()
        """Open the specified URL in a browser"""
        # Find an appropiate browser
        if os.path.exists("/usr/bin/xdg-open"):
            command = ["xdg-open", url]
        elif os.path.exists("/usr/bin/kde-open"):
            command = ["kde-open", url]
        elif os.path.exists("/usr/bin/exo-open"):
            command = ["exo-open", url]
        elif os.path.exists('/usr/bin/gnome-open'):
            command = ['gnome-open', url]
        else:
            command = ['x-www-browser', url]
        # Avoid to run the browser as user root
        if os.getuid() == 0 and 'SUDO_USER' in os.environ:
            command = ['sudo',
                       '--set-home',
                       '-u', os.environ['SUDO_USER']] + command
        subprocess.Popen(command)