Using Virtualenv with SublimeREPL

Setup:

• Sublime Text 3
• SublimeREPL (2.1.1) 
• Virtualenv (1.11.6)
• Mac OS X 10.7.5
• System Python (2.7.1) vs. Macports-installed Python (2.7.7)

Problem:

1. I want the SublimeREPL: Python to use a virtual environment
2. I want to use a different version of Python for my virtual environment

Note:
If you're a complete beginner at this, anything I wrote with ~$ means that's something done in Terminal.

Solution:

For problem #1: I want the SublimeREPL: Python to use a virtual environment

• From the SublimeREPL docs, it says you *must* use some Virtualenv wrapper for SublimeREPL to recognize your virtual environments.
• The docs suggested either virtualenvwrapper or venv.  I used venv, which works for me. I didn't try virtualenvwrapper.
• venv was easy to use. Just download the venv.bash file and save it anywhere you like and run it.
• For example, if you saved it in your home directory ~/, make sure the file is executable. If not, make it executable by: ~$ chmod +x venv.bash  To run it, do:
  
  ~$ source venv.bash
• Now, you can create your virtual environment. Let's say we want to make the environment called 'venv0':
  
  ~$ venv create venv0
  
  Notice, it will also automatically activate the environment:
  
  (venv0) ~$_
• The environment resides in:
  
  /Users/your_username/.venv/venv0
  
  *keep in mind I'm using OS X 10.7
• To start using the myenv environment from SublimeREPL (assuming it's already installed. If not, follow the SublimeREPL link on top):
• Launch Sublime Text 3
• Do: CMD+SHIFT+p
• Find the "SublimeREPL: Python - virtualenv" item from the list. (Shortcut: in the text field, start typing "virtualenv")
  
• Select "SublimeREPL: Python - virtualenv" (click, or use arrow key and hit enter if it's highlighted)
• Now venv0 ("/Users/your_username/.venv/venv0/bin/") should be showing in the view.
  
• Select venv0, and SublimeREPL will launch with the environment activated.

For problem #2: I want to use a different version of Python for my virtual environment

• Note: you cannot change your Python version if you already created your virtual environment. You will have to create a new environment, and reinstall all your module in the new environment.
• I have the default system Python (2.7.1), and just recently installed a newer version of Python (2.7.7) using Macports.
• The Macports' version of Python is installed in:
  
  /opt/local/bin/python2.7
• To use this alternative Python in your virtual environment, use the argument -p [path_to_python] with Virtualenv. For example
  
  ~$ virtualenv -p /opt/local/bin/python2.7 myenv
  
  Don't worry - it doesn't mean that the environment will start using a 'global' Python; it will still use the Python located in myenv/bin, but now that Python is the same version as the one in the path.
• To do this with venv, just modify the venv.bash file (using your text editor of choice). Find the line:
  
  virtualenv $@ --no-site-packages --distribute --prompt='$(__venv_prompt)'  "$VENV_DIR/$env"
  
  and change it to (emphasis added):
  
  virtualenv -p /opt/local/bin/python2.7 $@ --no-site-packages --distribute --prompt='$(__venv_prompt)'  "$VENV_DIR/$env"
  
  And save the file.
• For the changes to take effect, re-run the venv.bash again.
  
  ~$ source venv.bash
• Now, create another environment:
  
  ~$ venv create venv1
  (venv1) ~$_
  
  Run Python:
  
  (venv1) ~$ python
• You should see now venv1 is using the alternative Python version (in this case: 2.7.7). If you use the other environment (venv0), you can check that it's using 2.7.1.
• Finally, you can use venv1 from SublimeREPL as well.

Additional notes:

• To quit/exit/deactivate the virtual environment from venv:
  
  (venv0) ~$ deactivate
• To use/activate a virtual environment (e.g. venv0) using venv:
  
  ~$ venv use venv0
• To delete a virtual environment (e.g. venv0) using venv:
  
  ~$ venv destroy venv0

CAVEAT:

The big 'gotcha' here is that Sublime/SublimeREPL has its own weird way with the environment path. If you're using a virtual environment, SublimeREPL have no problem accessing any Python modules installed within the virtual environment.

If you have a global module you want to use, or a custom module you just made, you would have to add the path manually. I.e. (in SublimeREPL):

>>>  import sys

>>>  sys.path.append('/your_path/to/the/module')

I have not found a way to set the path to the libraries outside of the virtual environment to be included when launching SublimeREPL. Please let me know if you do.