ModuleNotFoundError: No module named 'psycopg2'

 I got this error when I'm trying to run odoo server 

ModuleNotFoundError: No module named 'psycopg2'

so to fix it , I run the commands bellow

sudo apt-get update
sudo apt-get install libpq-dev
sudo pip3 install psycopg2-binary

 & for runing odoo 15.0 with python 3.8 we can use 

sudo python3.8 -m pip install --upgrade psycopg2-binary 

The style compilation failed

When I'm trying to run odoo server , I'm facing this error The style compilation 

failed, see the error below. Your recent actions may be the cause, please try reverting the changes you made

So to fix it I run the commands bellow

sudo pip3 install libsass==0.12.3
sudo apt install python3-libsass