I found this info hard to find when making release 2.40 of my pygtk application FSlint. In that release I silenced various deprecation warnings emanating from python and GTK+. Now Python and GTK+ have good backwards compatibility, and silencing deprecation warnings introduced in new minor versions can be easily achieved. However every so often it's better to go with the flow, and increase the version required to both minimize deprecation hacks and maximize the features available.
In this particular case, newer GTK+ versions have started to deprecate the GtkFileSelection widget in favour of GtkFileChooser. After some searching I saw that this new widget was made available in GTK+ 2.4, but it was not immediately obvious what was the appropriate Python version to move up to. I picked Python 2.3, as suggested by the tables below.
Python releases
See the porting sections in the linked release notes below to summarize the features deprecated by each release.
| Major | Last Minor | Red Hat/Fedora |
| 1.5 Apr 1999 | 1.5.2 Apr 1999 | Red Hat 5.1 May 1998 |
| 1.6 Sep 2000 | 1.6.1 Sep 2000 | |
| 2.0 Oct 2000 | 2.0.1 Jun 2001 | |
| 2.1 Apr 2001 | 2.1.3 Apr 2002 | |
| 2.2 Dec 2001 | 2.2.3 May 2003 | Red Hat 8.0 Sep 2002 |
| 2.3 Jul 2003 | 2.3.7 Mar 2008 | Fedora Core 2 May 2004 |
| 2.4 Nov 2004 | 2.4.6 Dec 2008 | Fedora Core 4 Jun 2005 |
| 2.5 Sep 2006 | 2.5.4 Dec 2008 | Fedora 7 May 2007 |
| 2.6 Oct 2008 | 2.6.5 Mar 2010 | Fedora 11 Jun 2009 |
| 2.7 Jul 2010 | ||
| 3.0 Dec 2008 | 3.0.1 Feb 2009 | |
| 3.1 Jun 2009 | 3.1.2 Mar 2010 |
GTK+ releases
Note the output from glade-2 can be tweaked to suppress warnings on a particular GTK+ versions, and glade-3 can explicitly target particular GTK+ versions >= 2.8.
| Major | Last Minor | Red Hat/Fedora |
| 1.0 Apr 1998 | 1.0.6 Sep 1998 | Red Hat 5.1 May 1998 |
| 1.2 Feb 1999 | 1.2.10 Apr 2001 | Red Hat 6.0 Apr 1999 |
| 2.0 Mar 2002 | 2.0.9 Nov 2002 | Red Hat 7.3 May 2002 |
| 2.2 Dec 2002 | 2.2.4 Jun 2004 | Red Hat 9 Mar 2003 |
| 2.4 Mar 2004 | 2.4.14 Dec 2004 | Fedora Core 2 May 2004 |
| 2.6 Dec 2004 | 2.6.10 Aug 2005 | Fedora Core 4 Jun 2005 |
| 2.8 Aug 2005 | 2.8.20 Jul 2006 | Fedora Core 5 Mar 2006 |
| 2.10 Jul 2006 | 2.10.14 Jul 2007 | Fedora Core 6 Oct 2006 |
| 2.12 Sep 2007 | 2.12.12 Sep 2008 | Fedora 8 Nov 2007 |
| 2.14 Sep 2008 | 2.14.7 Jan 2009 | Fedora 10 Nov 2008 |
| 2.16 Mar 2009 | 2.16.6 Aug 2009 | Fedora 11 Jun 2009 |
| 2.18 Sep 2009 | 2.18.9 Mar 2010 | Fedora 12 Nov 2009 |
| 2.20 Mar 2010 | 2.20.0 Mar 2010 | Fedora 13 Apr 2010 |