Python Study Note (1)

Besides ordinary Python Manual reading, i would like to put some notes here to refresh my bad memory. There are many key words that i need to keep in mind when learning new computer language especially this language being a huge different compared to what i used for living(c, assembly).

Well skip the interpreter part which i see tiny chance of using it.

Typical python module definition file which have file extension of *.py have below format.

if you have multiple version of python install in your system, you can specify which version you want your program to run with.

#below  check your py.ini for defaults of "python" version

#! python  

#below specify the encoding of this python source file. utf-8 is default.

#-*-coding: utf-8-*-  


#then import some module you reference

import numpy

import sys,os


def fun1(a):

    pass


def main():

    pass


#below will use module file as script to run main, mainly for test purpose 

if __name__ == '__main__':

    main()  

There are some coding style that it would be nice to follow.

• Use 4-space indentation, and no tabs.
  4 spaces are a good compromise between small indentation (allows greater nesting depth) and large indentation (easier to read). Tabs introduce confusion, and are best left out.
  
• Wrap lines so that they don’t exceed 79 characters.
  This helps users with small displays and makes it possible to have several code files side-by-side on larger displays.
  
• Use blank lines to separate functions and classes, and larger blocks of code inside functions.
• When possible, put comments on a line of their own.
• Use docstrings.
• Use spaces around operators and after commas, but not directly inside bracketing constructs: 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.
• Don’t use fancy encodings if your code is meant to be used in international environments. Python’s default, UTF-8, or even plain ASCII work best in any case.
• Likewise, don’t use non-ASCII characters in identifiers if there is only the slightest chance people speaking a different language will read or maintain the code.