Questions[virtualenv](ubuntu)

I just installed python3.7 on my 18.04LTS via the deadsnakes ppa:

sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt install python3.7 -y

Now I want to create a virtual environment with python3.7 -m venv env but I get

Error: Command '['/path/to/desired/env/bin/python3.7', '-Im', 'ensurepip', '--upgrade', '--default-pip']' returned non-zero exit status 1.

python3 -m venv env0 worked fine before.

Why does this happen?
What can I do to create a virtual environment for python3.7 on Ubuntu 18.04LTS?

I recently upgraded to 20.04 from 19.10. Now i face issues since i need to use a virtual environment with Python 3.7 and cant seem to install the packages: - Python3.7-venv - Python 3.7-dev

Seems like these are not supported by 20.04.

Any way to install them for 20.04? Would they still have worked if i didnt do autoremove during the upgrade?

I hope to avoid having to reinstall 19.10.

I would like to start a python script from a virtual environment on startup. I have searched the whole forum and other sources but have not been able to make it work.

The script should run at the scripts directory as working directory and also the terminal that started the script should be kept visible.

I have mainly used the "Startup Applications" and different configurations of .desktop files in ~/user/.config/autostart

I have tried with running shell files that work on their own as the below:

[Desktop Entry]
Type=Application
Terminal=true
Exec=/home/user/autostart.sh
Hidden=false
NoDisplay=false
X-GNOME-Autostart-enabled=True
Name=autostart_shell
Comment=

And the .sh-file

#!/usr/bin/env bash
sleep 10
cd /home/user/environment
bin/python3 main.py
bash

or something like this

#!/usr/bin/env bash
sleep 10
cd /home/user/environment
source bin/activate 
python3 main.py
bash

However the environment never gets activated.

I have also tried other .desktop-configurations as below without success

[Desktop Entry]
Type=Application
Path=/home/user/env/
Terminal=true
Exec=gnome-terminal --command 'bash -ec "sleep 10;cd /home/user/env;source bin/activate;python3 main.py;bash"'
Hidden=false
NoDisplay=false
X-GNOME-Autostart-enabled=true

I've spent most of the day on this without any success, does anyone have any ideas?

UPDATE Ok, after some more work the problem is related to activating the virtual environment.

I'm using the "Startup Applications" to run a shell script. I have tried both the gnome-terminal and xterm with the same result. Below is the command in the *.desktop jobs

gnome-terminal --command '/home/user/folder/startup.sh'

and

xterm /home/user/folder/startup.sh

The shell script looks as follows:

#!/bin/bash
# Give it some time to make sure everything is loaded
sleep 5

# Logging to make sure it is run
TIMESTAMP=`date "+%Y-%m-%d %H:%M:%S"`
echo "$TIMESTAMP - program was run " >> /home/user/folder/log.txt

# Switching working directory
cd /home/user/folder

# Alternative 1 
# Run python script with virtual envirnments python binary
/home/user/folder/bin/python3 /home/user/folder/main.py

# Alternative 2
# Activate environment and then run 
source /home/user/folder/bin/activate
python3 /home/user/folder/main.py

# Keep the terminal open
bash

On boot and login the terminal is launched but a python error is displayed about a missing module. If the shell script is run standalone it works without a problem, but launched from the "Startup applications" it is not.

This is nagging me so hard, is it really not possible to start a terminal in a python virtual environment?

I am trying to install lalsuite on ubuntu according to the instructions here:

https://pycbc.org/pycbc/latest/html/install_lalsuite.html

Everything went smoothly until I ran

./00boot
./configure --prefix=${VIRTUAL_ENV}/opt/lalsuite --enable-swig-python

And the error I get is:

configure: error: could not find the zlib library

I am doing all this inside a virtual environment using virtualenv. I'm fairly certain I have the zlib library as I installed it with:

$ sudo apt install zlib1g

After a thorough search for a solution I found someone with the same problem:

https://ubuntuforums.org/showthread.php?t=2217198&page=2&s=3d14badd56b8ebb236dfc0970ba19435

But I do not really understand their solution. My interpretation of their fix was to do the following:

First reinstall pkg-config:

sudo apt-get update
sudo apt-get install pkg-config

Then write the line suggested by the answer:

echo 'export PKG_CONFIG=/usr/bin/pkg-config' >> ~/.bashrc

(I am doing all this inside the virtualenv by the way).

Then restart everything and try the same thing again:

./00boot
./configure --prefix=${VIRTUAL_ENV}/opt/lalsuite --enable-swig-python

Sadly the same error appears.

Any help is appreciated.

I want to make shell script that makes virtualenv, activates it, install some libraries and run python script with it.

But I have problem that I can't activate virtualenv in shell script unless i do "source script.sh" but then python3 doesn't work. How can I do something like this?

#!/bin/bash
python3 -m pip install virtualenv
python3 -m virtualenv virtual
source virtual/bin/activate
pip install <some libraries>
python <filename.py>

I would like to do this without any global paths to python. I want it to work locally.