[Tutor] Can't use packages in newly installed python 3.11.3

[Mats Wichmann]

On 4/11/23 10:15, Torbjörn Svensson Diaz wrote:
> Hello, dear tutors!
> 
> I recently installed Python 3.11.3 from source from an xz-file 
> downloaded from Python.org. I followed the instructions on 
> https://ubuntuhandbook.org/index.php/2021/10/compile-install-python-3-10-ubuntu/ and were successful in installing it. However, when I try to import numpy and scipy the following message prints:
> 
> 
> ModuleNotFoundError: No module named 'numpy'
> 
> I also have Python 3.10.6 installed and when I use that instead, I have 
> no problems importing numpy and scipy. Also, according to pip3 I have 
> numpy 1.21.5 and scipy 1.8.0 installed. (I ran "pip3 list".)
> What can i do to make my installed packages work in Python 3.11.3? Is it 
> a flaw to have two python 3s installed at the same time? What am I to 
> do? Please help me out!

No, it's fine.  But you need to have the packages you need for a given 
Python installation set up in that installation.

Let's say your newly built Python is accessible as python3.11. Do:

python3.11 -m pip list

If they're missing (as they certainly are, since you wouldn't be getting 
"No module" messages otherwise), install them the same way:

python3.11 -m pip install numpy

If your Python went to a system location (e.g. /usr/local/bin, which is 
common for Linux builds), install the numpy in your user account so you 
don't have to use "sudo" for installs:

python3.11 -m pip install --user numpy