cish 0.2.0

Write shell-like python scripts to control continuous builds.

I used to write small bash scripts that created the virtualenv and executed the python setup.py and nosetests commands using one of several Python versions I keep installed on my build machines. But bash scripts aren’t supported on Windows, so I want to write this script in Python instead.

cish is a set of utility functions to write bash-like python scripts that deal with several installed python interpreters.

Let’s get going!

import cish
cish.rm("build")
cish.default.pip("install", "nose")
cish.default.python("setup.py", "build")
cish.default.nosetests()

This will delete the build directory if it exists with all content, install nose, and build and test the package.

default is an ‘environment’ which consists of a python interpreter, library path, and utilities such as pip. default is the environent of the interpreter executing the script itself.

We can also use a different interpreter:

import cish
env = cish.from_interpreter("path/to/python")
env.python("setup.py", "build")
env.nosetests()

The installation location of the python interpreters is often dependent on the test machine. We can place a simple JSON file in one of several locations, for example in /etc/cish.json, to specifiy their location:

{
    "2.6.9": "/opt/python2.6.9/bin/python",
    "2.7.8": "/opt/python2.7.8/bin/python"
}

We can then choose the interpeter in our script using, say, an environment variable set by jenkins:

import cish, os
env = cish.from_config()[os.environ["PYTHON_VERSION"]]
env.python("setup.py", "build")

virtualenv is very easy too:

import cish
venv = cish.default.virtualenv("optional/location")
venv.pip("install", "package_to_install_inside_virtualenv")

Bug Reports and other contributions

This project is hosted here cish github page.

Alternatives

You might want to look at sh a cool library to run executables without dealing with subprocess directly. It has a far wider scope than cish but lacks the abstraction we offer for different python installations and OS specific file extensions and installation locations.