How I start and manage my python projects.

python_projects.md

How I organize my python projects

This is applicable to both OS X and Linux. I use the same tools on both systems. In this guide, I'm going to set up an environment for a Flask app.

Setup

1. I start by installing pip, virtualenv, then virtualenvwrapper. I seldom use virtualenv directly; I use the wrapper tools instead.

2. I create a virtualenv for my project:

   $ mkvirtualenv myflaskapp
   New python executable in myflaskapp/bin/python
   Installing setuptools............done.
   Installing pip...............done.
   

3. I then use pip to install any libraries that I need, e.g.:

   $ pip install flask
   $ pip install Flask-WTF
   

4. I then create a directory for my own python files (you can do this anywhere. I often just put this in my home directory).

   $ mkdir -p myflaskapp
   

5. And if I'm just building a simple project, or just doing some exploratory programming, I'll just write all of my code in a single main.py file.

   $ cd myflaskapp && touch main.py
   

6. Do some work in that file!

Coming back

Once I've stopped working on this project for a while, I'll come back to it, and reactivate my virtualenv:

workon myflaskapp

Now, If I need to install any other tools (like Flask-Mail), I can use pip to do so!

pip install Flask-Mail

And because I'm working in a project-specific virtual environment, my installed python libraries are separate from other projects.

Freezing & Re-creating your virtualenv

If you want to distribute your app, or if you want to work on another system, it's nice to be able to recreate your virtualenv. You do this by:

1. Freezing your requirements (with pip freeze)
2. Creating a new virtualenv and re-loading from a requirements file.

First, let's see what pip freeze does:

$ cd myflaskapp
$ pip freeze
Flask==0.10.1
Flask-WTF==0.9.5
Jinja2==2.7.2
MarkupSafe==0.23
WTForms==1.0.5
Werkzeug==0.9.4
dulwich==0.9.5
hg-git==0.5.0
itsdangerous==0.24
numpy==1.7.1
wsgiref==0.1.2

It just lists all of our install libraries (and their dependencies). You can save this in a requirements.txt file:

$ pip freeze > requirements.txt

Now, on any other system, you can create a new virtual environment:

mkvirtualenv myflaskapp

Then, re-install all of your libraries from a requirements file.

$ pip install -r requirements.txt

Thats it!

You can also take a look at pip help to see what else pip can do for you!

Good explanation. Where do you keep python, static etc. files? in virtualenv or outside of it? It's not clear for me from:

4. I then create a directory for my own python files (you can do this anywhere. I often just put this in my home directory).

@akimbekov He said he creates a directory inside the virtualenv directory. For example, he may create a folder called src inside myflaskapp.