Beginner's Guide: Python in Visual Studio Code (For Ubuntu)

Hello Guys,

This blog post is about how to use Visual Studio Code as an editor for Python language on Linux Operating System. Recently I came across VS Code and found it really beneficial. So, I decided why not try my hand on this and progressively share my working knowledge with you people. We are going to play with this awesome editor and try to learn its basic features and see what it offers.

VS Code is Free, Open source, and runs everywhere - Courtesy to Microsoft.

This blog is specifically directed for Ubuntu, however a lot of these steps will be common for other platforms too, as VS Code is available for Windows/Mac as well:

Firstly, we have to install VS Code by downloading the .deb package from official website and then by typing command on your terminal:

 “sudo apt install ./<file>.deb”

Or you can also follow the installation link from official website:

installation

Once the installation is done, you are good to go by launching the application and if you have followed all steps correctly you will get a welcome page as shown in pic.

welcome page

If you are seeing welcome page, you are good to go for next step 👍👍👍

Now let’s go through the basic layout for simple understanding.

 

Basic layout

 

Basic Layout (as described in official Microsoft Documentation)

VS Code comes with a simple and intuitive layout that maximizes the space provided for the editor while leaving ample room to browse and access the full context of your folder or project. The UI is divided into five areas:

1.    Editor - The main area to edit your files. You can open as many editors as you like side by side vertically and horizontally

2.    Side Bar - Contains different views like the Explorer to assist you while working on your project.

3.    Status Bar - Information about the opened project and the files you edit.

4.    Activity Bar - Located on the far left-hand side, this lets you switch between views and gives you additional context-specific indicators, like the number of outgoing changes when Git is enabled.

5.    Panels - You can display different panels below the editor region for output or debug information, errors and warnings, or an integrated terminal. Panel can also be moved to the right for more vertical space.

Each time you start VS Code, it opens up in the same state it was in when you last closed it. The folder, layout, and opened files are preserved.

Now we are going to achieve the main objective of this blog which is to configure and use VS Code for Python. So, let’s move forward and see what it holds for us 🙂

This blog is based on Python3 and we will learn how to run a simple python “Hello World” program in VS Code. VS Code is a lightweight Python IDE and proves itself as the productive alternative to some of the other available IDEs. We will learn how to edit, run Python code in this post. In upcoming posts I will show how to debug Python code easily and effectively in VS Code.

Lets get started:

Prerequisites:

1.    Install a version of Python3:

   As I am currently using “Ubuntu 18.04.1 LTS”, it comes with Python3, that’s why I don’t need to download it. So, make sure that your system has python3 installed by running command “python3 --version” in the terminal. 

pythonversion check

In case your system does not have Python3 installed, you can download it from official site python.org. Currently, you can use the Download Python 3.7.2 button that appears first on the page (or whatever is the latest version).

(Linux) The built-in Python 3 installation works well, but to install other Python packages you need pip.

pip is a package management system used to install and manage software packages written in Python. Many packages can be found in the default source for packages and their dependencies — Python Package Index (PyPI). ... pip is a recursive acronym for "Pip Installs Packages".

You can install pip with following command:

$ sudo apt update $ sudo apt install python3-pip

And once it’s installed, verify it by running the command below:

$ pip3 --version

The version number may vary but it looks something like this:

pipversion check

Install the Python extension for VS Code from VS Code Marketplace

VS Code Marketplace

The list of available Python Extensions will be displayed select and install the Python Extension provided by Microsoft as shown in image.

python extensions

Start VS Code in a project (workspace) folder (the Folder where you will be keeping your code in)

Open the terminal, create an empty folder called “demo”, navigate into it, and open VS Code (code) in that folder ( . ) by running the following commands-

create folder

By starting VS Code in a folder (here the folder is “demo”), that folder becomes your "Workspace". VS Code stores settings that are specific to that workspace in .vscode/settings.json, which are separate from user settings that are stored globally.

Alternately, you can run VS Code through the operating system UI, then use File > Open Folder to open the project folder. In following image, you can see that my current workspace is “DEMO” folder, that was create earlier. 

demo folder

Select a Python Interpreter:

Next very important step is to select a Python Interpreter as Python is an interpreted language. In order to have Python code run/test smoothly in VSCode, without switching to another terminal window, we need to tell VS Code which interpreter to use.

From VS Code, select a Python3 interpreter by opening the Command Palette (Ctrl+Shift+P), start typing the “Python: Select Interpreter” command to search.

select interpreter

The command presents a list of available interpreters that VS Code can find automatically, including virtual environments. If you don't see the desired interpreter, see Configuring Python environments.

select python environment

 

You can also use the Select Python Environment option on the Status Bar if available (it may already show a selected interpreter, too):

caution select python env

After choosing the desired Python default interpreter or python virtual environment, you will see the selected environment on status bar

selected python env

Create the first Python Hello World source code file

From the File Explorer toolbar, select the recently created folder “demo Folder” and click the New File button on it.

select new file option

Name the file as “hello.py”.

rename as hello.py

And the file hello.py automatically opens in the editor:

hello.py file

By using the .py file extension, you tell VS Code to interpret this file as a Python program, so that it evaluates the contents with the Python extension and the selected interpreter.

Next, start entering the following source code if using Python 3:

msg = “Hello World!” print(msg)

When you start typing “print” notice how IntelliSense presents auto-completion option

intellisense feature

IntelliSense and auto-completions work for standard Python modules as well as other packages you've installed into the environment of the selected Python interpreter. It also provides completions for methods available on object types. For example, because the msg variable contains a string, IntelliSense provides string methods when you type

msg.:

intellisense feature

Save the file(Ctrl+S)

Run Hello World

It's simple to run hello.py with Python. Right-click in the editor and select Run Python File in Terminal (which saves the file automatically):

run hello.py

The command opens a terminal panel in which your Python interpreter is automatically activated, then runs python3 hello.py

terminal output

This is your OS terminal in VS Code, where you can do almost anything that you would do in a normal terminal. No need to open one more terminal window…..One window to rule them all, pretty great – Right? (wink, wink).

There are two other ways you can run Python within VS Code:

1.    Select one or more lines, then press Shift+Enter or right-click and select Run Selection/Line in Python Terminal. This command is convenient for testing just a part of a file.

alternate way to run

python terminal

2.    Use the Python: Start REPL command (from Command Palette: Ctrl+Shift+P) to open a REPL terminal for the currently selected Python interpreter. In the REPL, you can then enter and run lines of code one at a time.
    
    A read–eval–print loop (REPL), also termed an interactive top level or language shell, is a simple, interactive computer programming environment that takes single user inputs (i.e., single expressions), evaluates them, and returns the result to the user; a program written in a REPL environment is executed piecewise.

select REPL

REPL terminal

   Now you can enter line by line code and run directly there. 

Well this is all for now, I will be continuing with "How to debug Python code in VS Code " in my next blog " Beginner's Guide: Debug Python Code on VS Code". Till then keep quenching your thirst for CODE... Thanks for your valuable time. Have a nice day :-) 😄

  

Note: THE INFORMATION PROVIDED IN THIS POST IS "AS IS" WITHOUT WARRANTY OF ANY KIND.