envie 0.4.19

Bash helpers for navigating and managing Python VirtualEnvs.

At its core, envie is a set of Bash functions aiming to increase your productivity when dealing with mundane VirtualEnv tasks, like: creating, destroying, listing, switching and activating environments.

But envie really shines when it comes to auto-discovery, auto-activation and auto-creation of VirtualEnvs relevant to your project (or executable). Just say:

~/work/projectA$ envie python tests.py

~/work/projectB$ envie manage.py migrate

~$ envie run python -c 'import os; print(os.getenv("VIRTUAL_ENV"))'

or use it in a hash bang:

#!/usr/bin/env envie

or, just import it at the beginning of your Python program:

#!/usr/bin/python
import envie.require

and in each of these cases the Python script will be executed in the closest virtual environment (for the definition of the closest environment see below, section Change/activate environment).

To just activate the closest virtual env, just type envie:

~/work/my-project-awesome$ envie

or even:

$ envie project awesome

(keywords filter all virtual envs in vicinity and activate the best match - if unique; if not unique you’re prompted to select the exact environment you wish to activate)

Summary

• envie create / mkenv [-2|-3|-p <pyexec>] [-r <pip_req>] [-i <pip_pkg>] [-a] [<envdir> | -t] -- [virtualenv opts] - Create virtualenv in <envdir> (or in temporary dir, -t) based on Python version <pyexec>, optionally install Pip packages from <pip_req> requirements file and <pip_pkg>> package specifier.

• envie remove / rmenv - Destroy the active environment.

• envie go / chenv [-1] [-q] [-v] [<basedir>] [<keywords>] - Interactively activate the closest environment (looking down, then up, with lsupenv), optionally filtered by a list of <keywords>. Start looking in <basedir> (defaults to .).

• envie list / lsenv [-f|-l] [<dir>|"." [<avoid>]] - List all environments below <dir> directory, skipping <avoid> subdir.

• envie find / lsupenv [-f|-l] [<dir>|"."] - Find the closest environments by first looking down and then dir-by-dir up the tree, starting with <dir>.

• cdenv - cd to the base dir of the currently active virtualenv ($VIRTUAL_ENV).

• envie [<basedir>] [<keywords>] - Activate the closest virtual environment (relative to <basedir>/cwd, filtered by KEYWORDS), but only if it’s unambiguous; shortcut for envie go -1 -v <keywords>.

• envie python <script>, envie <script> - Run python script in the closest virtual environment.

• envie run <command> - Execute arbitrary command/builtin/file/alias/function in the closest virtual environment.

• envie index - (Re-)index virtual environments (for faster searches with locate).

• envie config - Interactively configure envie.

• envie help - Print usage help. For details on a specific command use the ‘-h’ switch (like envie go -h).

Install

For convenience, envie is packaged and distributed as a Python package. To install, simply type:

$ sudo pip install envie
$ envie config

# start clean
$ . ~/.bashrc   # or, open a new shell

The second line above will run a short configuration/setup procedure. If in doubt, go with the defaults.

By default, envie sourcing statement is added to your .bashrc file, locate index is set as a preferred source (it’s set to be rebuilt every 15m, or on demand), with all relevant environments’ ancestor dir set to your $HOME directory.

Examples

Create/destroy

To create a new VirtualEnv in the current directory, just type mkenv <envname>. This results with new environment created and activated in ./<envname>. When done with this environment, just type rmenv to destroy the active env.

stevie@caracal:~/demo$ ls
stevie@caracal:~/demo$ mkenv env
Creating python environment in 'env'.
Using Python 2.7.9 (/usr/bin/python).
(env)stevie@caracal:~/demo$ ls
env
(env)stevie@caracal:~/demo$ pip freeze
argparse==1.2.1
wsgiref==0.1.2
(env)stevie@caracal:~/demo$ rmenv
stevie@caracal:~/demo$ ls
stevie@caracal:~/demo$

Create Python 3 environment in env and install pip packages from requirements.txt:

$ mkenv3 -r requirements.txt

Create a throw-away environment with pre-installed dev-requirements.txt and local project in editable mode from /home/stevie/work/mypackage/:

$ mkenv -t -r dev-requirements.txt -i "-e /home/stevie/work/mypackage/"

To automate the previous example, you can use envie-oneoff command in your hashbang, like this:

#!/usr/bin/env envie-oneoff
# -*- requirements: ./path/to/my/requirements.txt -*-

<your python code here>

When executed, a throw-away virtualenv is created, requirements specified are installed inside, code is run, and the environment is destroyed afterwards. Other way to do is directly: envie-oneoff SCRIPT.

Change/activate environment

Use chenv to activate the closest environment, tree-wise. We first look down the tree, then up the tree. If a single Python environment is found, it’s automatically activated. In case the multiple environments are found, a choice is presented to user.

stevie@caracal:~/demo$ ls -F
env/ project/ file1 file2 ...
stevie@caracal:~/demo$ chenv
(env)stevie@caracal:~/demo$

Assume the following tree exists:

~/demo
  |_ project1
  |  |_ env
  |  |  |_ ...
  |  |_ src
  |     |_ ...
  |_ project2
  |  |_ env
  |     |_ ...

Now, consider you work in ~/demo/project1/src/deep/path/to/module, but keep the environment in the env parallel to src. Instead of manually switching to env and activating it with something like source ../../../../../env/bin/activate, just type chenv (che<TAB> should actually do it, if you use tab completion):

stevie@caracal:~/demo/project1/src/deep/path/to/module$ chenv
(env)stevie@caracal:~/demo/project1/src/deep/path/to/module$ which python
/home/stevie/demo/project1/env/bin/python

On the other hand, if there are multiple environments to choose from, you’ll get a prompt:

stevie@caracal:~/demo$ chenv
1) ./project1/env
2) ./project2/env
#? 2
(env)stevie@caracal:~/demo$ which python
/home/stevie/demo/project2/env/bin/python

Search/list environments

To search down the tree for valid Python VirtualEnvs, use lsenv. Likewise, to search up the tree, level by level, use lsupenv. chenv uses lsupenv when searching for environment to activate.

Enable faster search

By default, envie uses the find command to search for environments. That approach is pretty fast when searching shallow trees. However, if you have a deeper directory trees, it’s often faster to use a pre-built directory index (i.e. the locate command). To enable a combined locate/find approach to search, run envie config:

$ envie config
Add to ~/.bashrc (strongly recommended) [Y/n]?
Use locate/updatedb for faster search [Y/n]?
Common ancestor dir of all environments to be indexed [/]:
Update index periodically (every 15min) [Y/n]?
Refresh stale index before each search [Y/n]?
Envie already registered in /home/stevie/.bashrc.
Config file written to /home/stevie/.config/envie/envierc.
Crontab updated.
Indexing environments in '/'...Done.

From now on, the combined approach is used by default (if not overriden with -f or -l switches). In the combined approach, if find doesn’t finish within 400ms, search via find is aborted and locate is allowed to finish (faster).