Wentao Liu wtracyliu

python项目通用组件和基础服务

很多公司都大量使用了python，其中有一些开发规范，code guidline，通用组件，基础框架是可以共用的。

每个公司都自己搞一套, 太浪费人力，我想开一帖和大家讨论一下这些python基础设施的搭建。

原则是我们尽量不重新发明轮子，但开源组件这么多，也要有个挑选的过程和组合使用的过程，在这里讨论一下。

另一方面，有些开源组件虽然强大，但我们不能完全的驾驭它，或只使用其中很少的一部分，我们就可以考虑用python实现一个简单的轮子，可控性更强，最好不要超过300行代码。

Synopsis

At the top of the file there should be a short introduction and/ or overview that explains what the project is. This description should match descriptions added for package managers (Gemspec, package.json, etc.)

Code Example

Show what the library does as concisely as possible, developers should be able to figure out how your project solves their problem by looking at the code example. Make sure the API you are showing off is obvious, and that your code is short and concise.

Motivation

libdispatch efficiency tips

The libdispatch is one of the most misused API due to the way it was presented to us when it was introduced and for many years after that, and due to the confusing documentation and API. This page is a compilation of important things to know if you're going to use this library. Many references are available at the end of this document pointing to comments from Apple's very own libdispatch maintainer (Pierre Habouzit).

My take-aways are:

You should create very few, long-lived, well-defined queues. These queues should be seen as execution contexts in your program (gui, background work, ...) that benefit from executing in parallel. An important thing to note is that if these queues are all active at once, you will get as many threads running. In most apps, you probably do not need to create more than 3 or 4 queues.
Go serial first, and as you find performance bottle necks, measure why, and if concurrency helps, apply with care, always validating under system pressure. Reuse

	#!/bin/bash

	# Source: http://toomuchdata.com/2012/06/25/how-to-install-python-2-7-3-on-centos-6-2/

	# Install stuff #
	#################

	# Install development tools and some misc. necessary packages
	yum -y groupinstall "Development tools"
	yum -y install zlib-devel # gen'l reqs

	// Use Gists to store code you would like to remember later on
	console.log(window); // log the "window" object to the console