This command works like AWK in one liners. It enables you to use Python modules on CLI. This is an example. $ seq 3 | opy '[math.log(F1)]' 0.0 0.6931471805599453 1.0986122886681098 Restriction: this snap version works with a python in the snap environment. Therefore, we cannot use the python in /bin and modules in`$PYTHONPATH`. When you want to use opy with the modules you installed, please install opy from GitHub (https://github.com/ryuichiueda/opy) with the commands below. I would appreciate it if you could click the star on the repository page. $ git clone https://github.com/ryuichiueda/opy.git $ cd opy $ sudo make install