Python Tips

My python tips with Django and Virtual Environment

Virtual Environment

A virtualenv allows you to modularize and run your python code without breaking the codebase of another app when upgrading a python module installed globally.

Any module you install in your virtual environment, will stay inside that virtual environment.

Never commit the venv/ dir to your source control (git). Only commit the requirements.txt file, which you can always generate using:
pip freeze > requirements.txt inside our environment. This will allow for any user to create the venv/ himself, and install the required modules for the project in that venv based on our file using pip install -r requirements.txt.

• Install virtualenv: pip3 install virtualenv
• Create a virtual env (preferably for each project — in the root dir of the same project):
  python3 -m virtualenv <new_environment_name> (preferably use venv for the name)
• And now whenever you are working with your project, activate your virtual environment using: source venv/bin/activate
– This will allow us to simply use python or pip instead of python3 or pip3, because our environment uses the same version of python we used to create the environment ;)
• To deactivate/exit an environment simply run deactivate.

Django

To run custom scripts either use this guide (Quick and Dirty — 2nd link) or write a custom django-admin command (Recommended — 1st Link).

Writing custom django-admin commands | Django documentation | Django

Standalone Django scripts: The definitive guide

Note that i'm not using python3 nor pip3 because i'm assuming that we are in an activated venv (See above for instructions on virtualenv).

• Install Django in your venv: pip install django
• Django basically consists of 1 project, many applications.
  E.g: Project: Google— Apps: search, images, etc…
• To create a project use:
  django-admin startproject <projectname>
• To create an application, navigate to the project dir and use:
  python manage.py startapp <appname> and install the app by navigating to <projectname>/<projectname>/settings.py and adding the <appname> into the INSTALLED_APPS array.
  
  * For every new application, you may want to create a new <appname>/urls.py file and include that inside tha main <projectname>/urls.py:

urlpatterns = [
   path("", include("<appname>.urls")
]

• To start the web server use: python manage.py runserver