Why Python Is Great: Subprocess — Running Linux Shell From Python Code.

Python is a brilliant object oriented programming language. In artificial intelligence/deep-learning circles, Python is often referred to as the default language (lingua franca) of artificial intelligence. But, the charm of Python extends way beyond running highly complicated deep-learning code. Python is first and foremost a general purpose programming language.

One of the key features of Python is its close integration with Linux. In this post I am going to explore one particular feature inside Python called ‘subprocess’. Subprocess, just like the name suggests initiates a linux shell command in python. This makes a lot of things easier inside Python, including, let us say, creating and manipulating file-system entries.

Here is a Python 3 function that utilizes subprocess to run a list of commands in linux terminal.

This function returns dictionary with two key values: Output and Error. Output records the console output, Error records the console error messages.

To run the function above, next, I will create a Python command:

This command will:

  1. Create a folder in Desktop called ‘New_photos’.
  2.  Randomly copy 10 .jpg files from  ~/Desktop/My_folder/Photos/ to ~/Desktop/New_photos/
  3.  Count the total number of files in the folder: ~/Desktop/New_photos/

 

That’s it. Running Linux commands inside python is as straightforward as passing a list of commands to a Python function.