VirtuAlias

VirtuAlias is a minimal wrapper for virtualenv. It will simply create a new alias (actually, a function) everytime you create a new environment, allowing you to switch between them. Functions are appended to a new file ~/.virtualias_functions.

Note that this is a pretty basic script. If you are looking for something more, then you are probably looking for virtualenvwrapper.

Please feel free to make new Pull Requests and provide suggestions: the main reason why I created VirtuAlias is to learn something new, so I will be grateful for every suggestion I will receive.

Installation

To install VirtuAlias on your system:

• download VirtuAlias using one of the following commands:

  git clone https://github.com/fievelk/virtualias
  # or
  curl -LOk https://github.com/fievelk/virtualias/archive/master.zip

  If you use the latest method, unzip the downloaded file.

• Change directory to the root virtualias (or virtualias-master) folder, then run the setup:

  python3 setup.py install

  The virtualias command should now be working on your system.

• Note: In order to use the functions defined in ~/.virtualias_functions for the first time, you need to re-login in the system or give the following command:

  source ~/.your_config_file
  

  depending on your configuration file (see table below).

  Available shells

  Shell	$SHELL	Config file
  Bash	/bin/bash	~/.bashrc
  Zsh	/bin/zsh	~/.zshrc

The function

VirtuAlias writes a function in ~/.virtualias_functions. The function is as simple as follows:

your_alias() {
    cd your/environment/folder;
    source your/environment/folder/bin/activate;
}

VirtuAlias will also append the following lines to your shell configuration file (depending on the $SHELL variable):

# VirtuAlias functions reference.
if [ -f ~/.virtualias_functions ]; then
    source ~/.virtualias_functions
fi

Usage

VirtuAlias can be used as you would use virtualenv, with an additional parameter -a (--alias). E.g.:

./virtualias.py -a=your_alias your_env_dir

In the above case, your new environment will be created in your_env_dir and you will be able to activate it using the alias (function) you specified (your_alias in the example above).

Is VirtuAlias an alternative to virtualenvwrapper?

VirtuAlias is just a personal experiment.

The reason why I wrote this script is that, as far as I know, virtualenvwrapper only allows you to switch between different environments created inside a pre-specified directory (WORKON_HOME variable). On the contrary, I needed to create my environments in several locations on my disk, so I decided to create this script that does not require any specific location. As stated above, if you are looking for something more, then you are probably looking for virtualenvwrapper.

Improvements

Some improvements are auspicable or necessary:

• source the configuration file after having written the function.

• Do we need to check for duplicate alias/function names in both the shell configuration file and the new ~/.virtualias_functions file?

• Provide a parameter to manually specify the shell configuration file (e.g. ~/.bashrc, ~/.zshrc, etc.).

• Create a wrapper around VirtuAlias so that the script is only executed when your Python version is >= 3. (A wrapper is needed in order to avoid SyntaxError problems. See this SO question)

• If the virtualenv call fails, we should not write the function in the shell configuration file. (At the moment, this is done using the delete_alias method. It would be better not to touch the configuration file at all instead.)

• Provide a method to remove aliases when we delete an environment.

• Add a specific file to store all aliases/functions (so that we do not mess too much with the shell configuration file). We could do this by adding the following in the shell configuration file:

  # Add VirtuAlias functions.
  if [ -f ~/.virtualias_functions ]; then
      source ~/.virtualias_functions
  fi

• Automatically detect shell (e.g. bash, zsh).

• Package (setup.py, etc.). Since this is a very small project, it may be not necessary.