How to install a module for all users with pip on linux?

You might have a wrong umask set as discussed here

From your last edit, I guess you umask is set to 027. Try to do

sudo pip uninstall loremipsum
umask 022
sudo pip install loremipsum

For Ubuntu 18.04 try sudo -H pip install loremipsum.

-H is the short form of --set-home:

-H, --set-home
     Request that the security policy set the HOME environment variable
     to the home directory specified by the target user's password 
     database entry.  Depending on the policy, this may be the default
     behavior.

In other words, this executes the sudo command with the HOME environment var set to root's home.

With Ubuntu 18.04, using the command sudo pip install stuff-name does not suffice, in my case, in order to install the modules in the global path (it keeps looking at the local-user python path).

Solution in my case

I have changed to the root user, and changed directory to its home. Then pip installation worked like expected and installs modules in the global path.

In detail I followed the nowox answer with a minor change (sudo su, changes to the root user), also see final note about umask 022:

sudo su
cd ~
umask 022
pip install what-you-like

Note: umask 022 command/row could be optional..., usually umask is already 022, that is the default one.