pip install vext.pygtk or add vext.pygtk to your requirements.txt
pygtk installed in the system python
Debian / Ubuntu
$ sudo apt-get install python-pygtk
SuSE
``` $ zypper install python-gtk``
Fedora, Redhat, Centos
$ yum install pygtk2
Windows
The pygtk all-in-one installer is work pretty well, there are other options - mixing them can cause issues.
Install it manually or if you have chocolatey you can just run choco install pygtk-all-in-one in a console window as Administrator.