Beginner’s Guide: Setting up the virtual environment in VS Code for different Python-based projects.

Hello Guys,

I know you must be waiting for my next blog so the wait is over and I am back to continue with my "Python Development in Visual Studio Code - Quick Tour" series. Today we are going to learn - how to set or create the virtual environment for different projects. But before we start its very necessary to know what is “Virtual Environment” and why a programmer really need to create one. So, let’s get digging 🤔

As described on the official Microsoft Documentation:

By default, any Python interpreter that you've installed run in its own global environment, which is not specific to any one project. For example, if you just run python (Windows) or python3 (macOS/Linux) at a new command prompt, you're running in that interpreter's global environment. Accordingly, any packages that you install or uninstall affect the global environment and all programs that you run within that context.

   Note: The Python Extension version 2018.8.1 and later automatically updates environments.

Although working in the global environment is an easy way to get started, that environment will, over time, become cluttered with many different packages that you've installed for different projects. Such clutter makes it difficult to thoroughly test an application against a specific set of packages with known versions, which is exactly the kind of environment you'd set up on a build server or web server.

For this reason, developers often create a virtual environment for a project. A virtual environment is a subfolder in a project that contains a copy of a specific interpreter. When you activate the virtual environment, any packages you install are installed only in that environment's subfolder. 

When you then run a Python program within that environment, you know that it's running against only those specific packages.

Let’s 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.

 

      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).

    2. (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:

 

Note: Make sure that whenever you start a python-based project you must have created your virtual environment before installing any package respective to that project. This will help your project packages to be refined within that virtual environment i.e. at one place.

Creating Virtual Environment

To create a virtual environment, in your project folder first you need to create your project folder for example “myproject”.  Now run the following command in your terminal to create the virtual environment in your project folder here its “myproject”.

$ sudo apt-get install python3-venv

 

$ python3 -m venv myenv

Where "myenv" is the name of the environment folder.

Now, Open the project folder in VS Code by running “code .”,

or, by running VS Code Application and using the option File > Open Folder.

Now we are required to set Python Environment and if you remember we already did this step in my first blog. So we will follow the same steps but here it’s a slight change - we are going to select our newly created virtual environment “myenv” as our current python environment instead of selecting global environment.

In VS Code, open the Command Palette (Ctrl+Shift+P) and then select the Python: Select Interpreter command:

The command presents a list of available interpreters that VS Code can locate automatically. The newly created virtual environment will now be available in this list. From the list, select the virtual environment in your project folder that starts with ./myenv or .\myenv:

Run Terminal: Create New Integrated Terminal (Ctrl+Shift+`) from the Command Palette, which creates a terminal and automatically activates the virtual environment by running its activation script.

The selected environment appears on the left side of the VS Code status bar, and notice the "(venv)" indicator that tells you that you're using a virtual environment:

So, at the time of deployment of your application to other computers, you can create a requirements.txt file with the command 

$ pip3 freeze > requirements.txt

The requirements file contains all the information and name of all the packages you've installed in your virtual environment. With only this file, you or other developers can restore those packages.

$ pip3 install -r requirements.txt

By using a requirements file, you need not commit the virtual environment itself to source control.

This how a virtual environment is created and is used in VS Code. Well that’s all for now, I will be continuing with "How to start a project in Django in VS Code” in my next blog " Beginner's Guide: Starting a Django Project in 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.