What would cause the "gi" module to be missing from Python?

Question

After some not so clever editing of the default Python version in Ubuntu, from 2.7 to 3.2, I ended up breaking my entire system. After my computer imploded and everything stopped working, I tried to revert back my changes (by linking /usr/bin/python2.7 to /usr/bin/python and changing the default version in /usr/share/python/debian_defaults back to 2.7) but some things are still broken.

For example, when I type import gi in the Python interpreter I get the following message:

>>> import gi
 Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
 ImportError: No module named gi
>>> 

error which appears with some programs too (eg: gnome tweak tool). I have tried re-installing Python both from the software center and from sources, but the same error persists.

python --version now returns:

 Python 2.7.2

and also some software packages which depend on Python 2.7 are now working (for example the software center), but some things are still broken. Is there anything I can do to completely re-install Python 2.7 as the default version?

Solution 1

I've found three ways to do this:

1. The simple way:

   sudo apt install python3-gi
   

2. The vext way, for virtualenv users:

   pip install vext
   pip install vext.gi
   

3. The pure Python developer way:

   Install a bunch of developer stuff:

   sudo apt install pkg-config libcairo2-dev gcc python3-dev libgirepository1.0-dev
   

   Install the python packages:

   pip install gobject PyGObject
   

Solution 2

If you installed anaconda and it has become the default python environment, gi module can be installed via:

conda install -c conda-forge pygobject 

Also see: https://bugs.launchpad.net/ubuntu/+source/ibus/+bug/1611523

Solution 3

Little workaround found here that worked for me:

sudo nano /usr/bin/gnome-tweak-tool

Change #!/usr/bin/env python to #!/usr/bin/python

Solution 4

Run this command in the terminal:

sudo apt install python3-gi

or if you need Python2 support instead:

sudo apt install python-gi

Solution 5

sudo apt-get install -y python-gobject

Fixed it for me on Ubuntu 18.04.

View more solutions

Comments

[Javier Rivera]

Have you tried to reinstall python-gobjects ?

[Colin Dumitru]

I did, but it re-installed "python-gobject 3.0.0-0ubuntu4". Is this the correct version number for 2.7?

[sagarchalise]

have you tried reconfiguring python i.e. sudo dpkg-reconfigure python2.7 ?

[Colin Dumitru]

Yes, but the same error persists.

[Aris]

for those have updated python to 3.7 manually, all you have to do is to edit /usr/bin/gnome-tweaks, and: change the #!/usr/bin/python3 to #!/usr/bin/python3.6. Everything should work like a charm after this

[Matthew]

In this case the packages are shared - so works for both. Have removed the reference to Debian to avoid confusion.

[ArchLinuxTux]

This solved the problem for me on Arch Linux! The other solution by Jeremy Bicha, installing python-gobject on Arch Linux (or python3-gi on Ubuntu) did not work for me!

[matanster]

Only way that worked for me this time around

[Doğuş]

Caution: if you do install "python3-dev", it may upgrade your already installed python3, and might create complications for you, as it happened to me previously.

[Cerin]

Installing the vext packages in my virtualenv only changed the error to ImportError: cannot import name '_gi' from 'gi' (/usr/lib/python3/dist-packages/gi/__init__.py)