(首页)开始编程之旅 翻译自Lee Harr的Start Programming 本文是使用pygsear+pygame作为开发环境,以初级用户角度来分步分阶段学习PYTHON基本概念,并以小游戏开发项目为具体案例,介绍的十分详细。编写风格清新朴实,没有象一般教科书那样枯燥,极其适合初级用户来激发兴趣时使用。
Contents
1. StartProgramming-2-1 引入Import
At the top of most Python programs, you will see import statements like this:
在大部分的Python程序的开头,你都会看到 import 语句:
1 import random
2 import os.path
3 from math import sqrt
4 from penguin import *
The import statement lets you quickly and easily load in python modules.
import 语句可以使我们快速并且简单在python中的加载组件.
Modules are useful code that is already written -- either code which someone else wrote or your own code. Before starting any programming project, it is a good idea to look around and see if there is already a module which will do what you need.
组件是已经写过的有用的代码 -- 在别人写的代码和你的代码之间。在开始一个编程项目之前,看一看有没有你需要用的已经写过的组件是一个不错的主意。
Why would you want to import a module?
你为什么想要导入一个组件?
If you need to make your game behave randomly, you might want to choose from different attack strategies:
如果你想要你的游戏表现的很随机,你可能想要选择不同的攻击策略:
1 import random
2 strategies = ['aggressive', 'cautious', 'defensive']
3 strategy = random.choice(strategies)
Or, if your game needs to know the size of a file:
或者,假如你的游戏需要知道文件的大小:
1 import os.path
2 os.path.getsize('.')
Or, if you need to know the distance between two objects:
或者,假如你想要知道两个物体之间的距离:
1 from math import sqrt
2 x0, y0 = (150, 75)
3 x1, y1 = (275, 300)
4 distance = sqrt((x0 - x1)**2 + (y0 - y1)**2)
This distance formula (the Pythagorean Theorem) is so useful that it is included in the math module:
这个距离运算(毕达格拉斯定理)是如此的有用,所以它已经被收录到 math 组件当中了:
1 import math
2 distance2 = math.hypot((x0 - x1), (y0 - y1))
You can see the values, and check if they are the same:
你能够看到变量的值,并且检查它们是否相等:
1 print distance, distance2, distance == distance2
Or, if you just want to use the penguin graphics module:
或者,假如你正想使用企鹅绘图组件:
1 from penguin import *
2 pete.star()