排除空值以便将一个列表除以另一个列表

Question

我有两个列表：total_price和units_b，它们都包含空值，我有一个表达式将total_price除以units_b：

    total_price = [None, None, 10, 20]
    units_b = [None, None, 1, 2]

    average_price = [(x/y) for x, y in zip(total_price, units_b)]

尝试运行average_price会给我一个错误，说我不能分为两个'NoneTypes'。有什么方法可以排除除法的空值但是坚持原始列表的完整性？

Answer 1

average_price = [(x/y) for x, y in zip(total_price, units_b) if x is not None and y is not None]

Answer 2

total_price = [None, None, 10, 20]
units_b = [None, None, 1, 2]

average_price = [(x/y) for x, y in zip(total_price, units_b) if x is not None and y is not None]

Answer 3

average_price = [(x/y) for x, y in zip(total_price, units_b) if not (x==None or y==None)]

虽然你应该read the docs