Ex19 Functions and Variables

函数与变量

Ex19 继续练习函数的用法。有一点在 Ex19 里需要注意: 定义函数时，用到的变量名。在正是使用函数时，可以在括号里填写其他变量名。细节见练习。

示例代码 Ex19:

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def cheese_and_crackers(cheese_count, boxes_of_crackers):
    print "You have %d cheeses!" % cheese_count
    print "You have %d boxes of crackers !" % boxes_of_crackers
    print "Man that's enough for a party!"
    print "Get a blanket.\n"
print "we can just gibe the function numbers directly:"
cheese_and_crackers(20, 30)
print "OR, we can use variables from our script:"
amount_of_cheese = 10
amount_of_crackers = 10
cheese_and_crackers(amount_of_cheese, amount_of_crackers)

print "we can do math 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)

代码运行结果:

小结

在 C 语言里面，关于函数，提到过“形参”和 “实参”。Python 语言也是类似的规矩。定义 Function 使用的变量名与运行 Function 使用的变量名可以不同。Python另一个灵活之处，是可以在运算表达式的结果当作参数传递给Function。