Learn Python The Hard Way学习(19) - 函数和变量
函数包含比较多的东西，很难一下理解，不过不用担心，对照上一节的检查清单练习，最后会明白的。
这里有个细节可能你没注意到，我们现在加强一下：函数里面的变量和脚本中的变量是没有关联的。
看下面的程序：def cheese_and_crackers(cheese_count, boxes_of_crackers): print "You have %d cheeses!" % cheese_count print "You hava %d boxes of crackers!" % boxes_of_crackers print "Man that's enough for a party!" print "Get a blanket.\n"print "We can just give the function numbers directly:"cheese_and_crackers(20, 30)print "OR, we can use variables from our script:"amount_of_cheese = 10amount_of_crackers = 50cheese_and_crackers(amount_of_cheese, amount_of_crackers)print "We can even do match inside too:"cheese_and_crackers(10 + 20, 5 + 6)print "And we can combine the two,variables and math:"cheese_and_crackers(amount_of_cheese + 100, amount_of_crackers + 1000)
上面展示所有不同的调用cheese_and_crackers函数的方法。
函数中的参数和变量类似，变量赋值的时候用=，函数也是这样给参数赋值。
运行结果root@he-desktop:~/mystuff# python ex19.py We can just give the function numbers directly:You have 20 cheeses!You hava 30 boxes of crackers!Man that's enough for a party!Get a blanket.
OR, we can use variables from our script:You have 10 cheeses!You hava 50 boxes of crackers!Man that's enough for a party!Get a blanket.
We can even do match inside too:You have 30 cheeses!You hava 11 boxes of crackers!Man that's enough for a party!Get a blanket.
And we can combine the two,variables and math:You have 110 cheeses!You hava 1050 boxes of crackers!Man that's enough for a party!Get a blanket.
root@he-desktop:~/mystuff#
加分练习1. 给脚本添加注释。
2. 反过来读一下代码。
3. 自己写一个函数，然后用10种方法调用。