@one_employee
When you installed bs4 with easy_instal, you installed it system-wide. So your system python can import it, but not your virtualenv python. If you do not need bs4 to be installed in your system python path, uninstall it and keep it in your virtualenv.
I will advise you to uninstall the bs4 library by using this command:
pip uninstall bs4
and then install it using this command:
sudo apt-get install python3-bs4