launch.py: Add a --path arg to set PYTHONPATH

Author: ferdnyc

src/launch.py

@@ -1,46 +1,47 @@
 #!/usr/bin/env python3
 
-""" 
+"""
  @file
  @brief This file is used to launch OpenShot
  @author Jonathan Thomas <[email protected]>
  @author Noah Figg <[email protected]>
- 
+
  @mainpage OpenShot Video Editor 2.0
- 
+
  Welcome to the OpenShot Video Editor 2.0 PyQt5 documentation. OpenShot was developed to
  make high-quality video editing and animation solutions freely available to the world. With a focus
  on stability, performance, and ease-of-use, we believe OpenShot is the best cross-platform,
  open-source video editing application in the world!
- 
- This documentation is auto-generated by Doxygen, using the doxypy Python filter. If you are 
- interested in how OpenShot Video Editor is designed, feel free to dive in, because this 
+
+ This documentation is auto-generated by Doxygen, using the doxypy Python filter. If you are
+ interested in how OpenShot Video Editor is designed, feel free to dive in, because this
  documentation was built just for you. If you are not a developer, please feel free to visit
- our main website (http://www.openshot.org/download/), and download a copy today for Linux, Mac, or Windows. 
+ our main website (http://www.openshot.org/download/), and download a copy today for Linux, Mac, or Windows.
 
  @section LICENSE
- 
+
  Copyright (c) 2008-2018 OpenShot Studios, LLC
  (http://www.openshotstudios.com). This file is part of
  OpenShot Video Editor (http://www.openshot.org), an open-source project
  dedicated to delivering high quality video editing and animation solutions
  to the world.
- 
+
  OpenShot Video Editor 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 3 of the License, or
  (at your option) any later version.
- 
+
  OpenShot Video Editor 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 OpenShot Library.  If not, see <http://www.gnu.org/licenses/>.
  """
 
 import sys
+import os.path
 from argparse import ArgumentParser, REMAINDER
 
 try:
@@ -65,6 +66,10 @@ def main():
     parser.add_argument('--list-languages', dest='list_languages',
                         action='store_true', help='List all language '
                         'codes supported by OpenShot')
+    parser.add_argument('--path', dest='py_path',
+                        action='append',
+                        help='Additional locations to search for modules '
+                        '(PYTHONPATH). Can be used multiple times.')
     parser.add_argument('-V', '--version', action='store_true')
     parser.add_argument('remain', nargs=REMAINDER)
 
@@ -82,6 +87,18 @@ def main():
             print("  {:>12}  {}".format(lang[0],lang[1]))
         sys.exit()
 
+    if args.py_path:
+        for p in args.py_path:
+            try:
+                if os.path.exists(os.path.realpath(p)):
+                    sys.path.insert(0, os.path.realpath(p))
+                    print("Added {} to PYTHONPATH".format(os.path.realpath(p)))
+                else:
+                    print("{} does not exist".format(os.path.realpath(p)))
+            except TypeError as ex:
+                    print("Bad path {}: {}".format(p, ex))
+                    continue
+
     if args.lang:
         if args.lang in info.SUPPORTED_LANGUAGES:
             info.CMDLINE_LANGUAGE = args.lang