enw - Environment Wrapper

enw is a wrapper tool for quick creation and switching between different python virtual environments. In particular it allows for:

• Quick creation of new environments using virtualenv.
• Automatic linking of said environment autoenv, but without destroying local autoenv directives.
• Quick switching between python installation.
• Auto pip installation of programs that you know you want in all new environments (like e.g. ipython).
• Quick reinstallations.

Obviously, all of this can be done by hand, but the idea is to simplify the process that you keep doing many times, and do so in a way that is tractable.

Note that the core functionality of enw adds and replaces what python to source in .env files. It does so carefully so that other content that you may have added to the file is not affect.

Installation

To install, run the following outside of any virtual environment::

pip instal enw

This will install the dependencies virtualenv and autoenv. The latter has to be activated (as normal) by running something like::

echo "source `which activate.sh`" >> ~/.bashrc

or if on a mac::

echo "source `which activate.sh`" >> ~/.bash_profile

enw will install environments, but by default will not activate them. If you want it to also handle activation, you need to add a trigger for autoenv like so::

echo "function enw(){ envwrap "$@";autoenv_init; }" >> ~/.bash_aliases

(Make sure that .bashrc/.bash_profile sources the content of .bash_aliases for this to work.)

Usage

For basic usage, run the basic wrapper::

enw

It will create a virtual environment (which default to python3) under the folder name .py3. A line sourcing of the file .py3/bin/activate will be placed in a file .env. This will activate the environment everytime you enter the folder or one of its subfolders.

If you want to use another python version, this is possible by adding a positional version number. For example::

enw 2.7

It will then repeat the whole process, but with the folder .py27. To switch back to Python 3 setup, just run::

enw 3

If you do want to reinstall an environment, this is also possible::

enw -f 2.7

In addition, if if is possible to use enw to install a suite of standard packages. By including a -i flag, enw will look for the file .enw recursivly in the current directory and bellow it (much like autoenv) and install its content using pip install -r, using the newly installed virtual environment.