styn 1.0.0

Lightweight Python Build Tool for Celery Users.

A styn of Python build.

Lenny Morayniss

Features

• Easy to learn.

• Build tasks are just python functions.

• Manages dependencies between tasks.

• Automatically generates a command line interface.

• Rake style param passing to tasks

• Supports python 2.7 and python 3.x

• Tasks are called chores.

• Works with Celery.

Installation

You can install styn from the Python Package Index (PyPI) or from source.

Using pip

$ pip install styn

Using easy_install

$ easy_install styn

Example

The build script is written in pure Python and styn takes care of managing any dependencies between tasks and generating a command line interface.

Writing build tasks is really simple, all you need to know is the @task decorator. Tasks are just regular Python functions marked with the @task() decorator. Dependencies are specified with @task() too. Tasks can be ignored with the @task(ignore=True). Disabling a task is an useful feature to have in situations where you have one task that a lot of other tasks depend on and you want to quickly remove it from the dependency chains of all the dependent tasks.

build.py

#!/usr/bin/python

import sys
from styn import chore

@chore()
def clean():
    '''Clean build directory.'''
    print 'Cleaning build directory...'

@chore(clean)
def html(target='.'):
    '''Generate HTML.'''
    print 'Generating HTML in directory "%s"' %  target

@chore(clean, ignore=True)
def images():
    '''Prepare images.'''
    print 'Preparing images...'

@chore(html,images)
def start_server(server='localhost', port = '80'):
    '''Start the server'''
    print 'Starting server at %s:%s' % (server, port)

@chore(start_server) #Depends on task with all optional params
def stop_server():
    print 'Stopping server....'

@chore()
def copy_file(src, dest):
    print 'Copying from %s to %s' % (src, dest)

@chore()
def echo(*args,**kwargs):
    print args
    print kwargs

# Default task (if specified) is run when no task is specified in the command line
# make sure you define the variable __DEFAULT__ after the task is defined
# A good convention is to define it at the end of the module
# __DEFAULT__ is an optional member

__DEFAULT__=start_server

Running styn chores

The command line interface and help is automatically generated. Task descriptions are extracted from function docstrings.

$ styn -h
usage: styn [-h] [-l] [-v] [-f file] [task [task ...]]

positional arguments:
  task                  perform specified task and all its dependencies

optional arguments:
  -h, --help            show this help message and exit
  -l, --list-tasks      List the tasks
  -v, --version         Display the version information
  -f file, --file file  Build file to read the tasks from. Default is
                        'build.py'

$ styn -l
Tasks in build file ./build.py:
  clean                       Clean build directory.
  copy_file
  echo
  html                        Generate HTML.
  images           [Ignored]  Prepare images.
  start_server     [Default]  Start the server
  stop_server

Powered by styn - A Lightweight Python Build Tool for Celery Users.

styn takes care of dependencies between tasks. In the following case start_server depends on clean, html and image generation (image task is ignored).

$ styn #Runs the default task start_server. It does exactly what "styn start_server" would do.
[ example.py - Starting task "clean" ]
Cleaning build directory...
[ example.py - Completed task "clean" ]
[ example.py - Starting task "html" ]
Generating HTML in directory "."
[ example.py - Completed task "html" ]
[ example.py - Ignoring task "images" ]
[ example.py - Starting task "start_server" ]
Starting server at localhost:80
[ example.py - Completed task "start_server" ]

The first few characters of the task name is enough to execute the task, as long as the partial name is unambiguous. You can specify multiple tasks to run in the commandline. Again the dependencies are taken taken care of.

$ styn cle ht cl
[ example.py - Starting task "clean" ]
Cleaning build directory...
[ example.py - Completed task "clean" ]
[ example.py - Starting task "html" ]
Generating HTML in directory "."
[ example.py - Completed task "html" ]
[ example.py - Starting task "clean" ]
Cleaning build directory...
[ example.py - Completed task "clean" ]

The ‘html’ task dependency ‘clean’ is run only once. But clean can be explicitly run again later.

styn tasks can accept parameters from commandline.

$ styn "copy_file[/path/to/foo, path_to_bar]"
[ example.py - Starting task "clean" ]
Cleaning build directory...
[ example.py - Completed task "clean" ]
[ example.py - Starting task "copy_file" ]
Copying from /path/to/foo to path_to_bar
[ example.py - Completed task "copy_file" ]

styn can also accept keyword arguments.

$ styn start[port=8888]
[ example.py - Starting task "clean" ]
Cleaning build directory...
[ example.py - Completed task "clean" ]
[ example.py - Starting task "html" ]
Generating HTML in directory "."
[ example.py - Completed task "html" ]
[ example.py - Ignoring task "images" ]
[ example.py - Starting task "start_server" ]
Starting server at localhost:8888
[ example.py - Completed task "start_server" ]

$ styn echo[hello,world,foo=bar,blah=123]
[ example.py - Starting task "echo" ]
('hello', 'world')
{'blah': '123', 'foo': 'bar'}
[ example.py - Completed task "echo" ]

Organizing build scripts

You can break up your build files into modules and simple import them into your main build file.

from deploy_tasks import *
from test_tasks import functional_tests, report_coverage

Contributors/Contributing

• Raghunandan Rao - styn is preceded by and forked from pynt, which was created by Raghunandan Rao.

• Calum J. Eadie - pynt is preceded by and forked from microbuild, which was created by Calum J. Eadie.

If you want to make changes the repo is at https://github.com/ldmoray/styn. You will need pytest to run the tests

$ ./b t

It will be great if you can raise a pull request once you are done.

If you find any bugs or need new features please raise a ticket in the `issues section <https://github.com/ldmoray/styn/issues>`__ of the github repo.

Really, this is just a downstream fork to rename “tasks” to “chores” though.

License

pynt is licensed under a MIT license

Changes

1.0.0 - 30/03/2016

• Rename task decorator to chore to work with Celery.

• Use default “py.test” to test. Only test one version.

Changes before forking from pynt

0.8.1 - 02/09/2013

• Enabling extensions

0.8.0 - 02/09/2013

• Support for specifying a default task with __DEFAULT__ variable

• pynt -v (–version) for displays version info

• pynt -l lists tasks in alphabetical order

0.7.1 - 17/03/2013

• Migrated pynt to work on python 3.x. pynt still works on 2.7.

• pynt version now displayed as part of help output.

0.7.0 - 16/02/2013

• New commandline interface. Distribution now includes ‘pynt’ executable.

• ‘build.py’ is the default build file.

• Build files no longer need “if main” construct.

• pynt no longer exposes build method. This is a backward incompatible change.

0.6.0 - 17/12/2012

• Simplified ignoring tasks. ignore a keyword param for task and not a separate decorator. [This change is NOT backward compatible!!!]

• Added support for listing tasks

• Improved help

0.5.0 - 01/12/2012

• Ability to pass params to tasks.

• Major rewrite and flattening the package hierarchy.

0.4.0 - 17/11/2012

• Support for running multiple tasks from commandline.

• Ability to run tasks by typing in just the first few unambigious charecters.

Changes before forking from microbuild

0.3.0 - 18/09/2012

• Fixed bug in logging. No longer modifies root logger.

• Added ignore functionality.

• Extended API documentation.

0.2.0 - 29/08/2012

• Added progress tracking output.

• Added handling of exceptions within tasks.

0.1.0 - 28/08/2012

• Initial release.

• Added management of dependancies between tasks.

• Added automatic generation of command line interface.