Python 代码风格 & Python coding style

from 《Python 2.7.9 documentation》

- Use 4-space indentation, and no tabs.  
使用4空格缩进，不要使用tab缩进

- Wrap lines so that they don’t exceed 79 characters.  
拆行确保每行不超过79个字符

- Use blank lines to separate functions and classes, and larger blocks of code inside functions.  
函数和类之间用空行隔开，包括大块代码段也用空行隔开

- When possible, put comments on a line of their own.  
注释单独占一行

- Use docstrings.  
使用文档字符串

- Use spaces around operators and after commas, but not directly inside bracketing constructs: a = f(1, 2) + g(3, 4).  
操作符两侧和逗号后面留空格，但括号里侧不加空格：a = f(1, 2) + g(3, 4)

- Name your classes and functions consistently; the convention is to use CamelCase for classes and lower_case_with_underscores for functions and methods. Always use self as the name for the first method argument (see A First Look at Classes for more on classes and methods).  
统一类名和函数名，推荐类名用驼峰命名：SampleClass，函数名用小写和下划线命名：get_page()，尽量用self作为方法的第一个参数

- Don’t use fancy encodings if your code is meant to be used in international environments. Plain ASCII works best in any case.
国际化环境中慎用编码，ASCII最佳。（中文环境下，推荐utf-8）