100+Python挑战性编程练习系列 -- day 12

Question 44

编写一个程序，它可以使用map（）来创建一个列表，列表中的元素是1到20之间的数字的平方（包括两者）。

def sqr(x): return x*x squaredNumbers = list(map(sqr, range(1,21))) print(squaredNumbers) 

Question 45

定义一个名为American的类，它有一个名为printNationality的静态方法。

class American(): @staticmethod def printNationality(): print("I am American") american = American() american.printNationality() # this will not run if @staticmethod does not decorates the function. # Because the class has no instance. American.printNationality() # this will run even though the @staticmethod # does not decorate printNationality() 

Question 46

定义一个名为American的类及其子类NewYorker。

class American(): pass class NewYorker(American): pass american = American() newyorker = NewYorker() print(american) print(newyorker)