gallery.py: Add a 'version' argument

With the 'version' action [1], instead of passing the version as an
argument to ArgumentParser (which was at one point supported in
Python, but I can't find the deprecation docs).

[1]: https://docs.python.org/3/library/argparse.html#action
[2]: https://docs.python.org/3/library/argparse.html#argparse.ArgumentParser

diff --git a/posts/gallery/gallery.py b/posts/gallery/gallery.py
index 3b3ed1df22fd4bd1d9f296521ac7102b5b337746..760768fa7d76eb0a966170ae83cbfb97281cdf4f 100755 (executable)
--- a/posts/gallery/gallery.py
+++ b/posts/gallery/gallery.py
@@ -827,8 +827,11 @@ if __name__ == '__main__':
     import argparse as _argparse
 
     parser = _argparse.ArgumentParser(
-        description=__doc__, version=__version__,
+        description=__doc__,
         formatter_class=_argparse.RawDescriptionHelpFormatter)
+    parser.add_argument(
+        '--version', action='version',
+        version='%(prog)s {}'.format(__version__))
     parser.add_argument(
         '--mode', default='cgi', choices=['cgi', 'scgi', 'wsgi'],
         help='Server mode (defaults to CGI)')