使用python helper函数从循环中排除数字


Using Python helper function exclude numbers from a loop

给定3个int值，a b c返回它们的和。但是，如果其中任何一个值是青少年(包括13-19)，则该值计为0，除了15和16不计为青少年。编写一个单独的助手"def fix teen(n)："，它接受一个int值并返回为teen规则固定的值。这样，您就可以避免重复青少年代码3次(即"分解")。

Define the helper below and at the same indent level as the main no_teen_sum().Again, you will have two functions for this problem!

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def no_teen_sum(a, b, c):
  # CODE GOES HERE
def fix_teen(n):
  # CODE GOES HERE

实例：

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*no_teen_sum(1, 2, 3) → 6
*no_teen_sum(2, 13, 1) → 3
*no_teen_sum(2, 1, 14) → 3
*no_teen_sum(2, 16, 1) → 19

我拿到第一部分了

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def no_teen_sum(a, b, c):
    total = 0
    for i in (a, b, c):
        if i in range(13, 20):
            x = 0
        else:
            x = 1
        total += i*x
    return total

只是在第二个问题上挣扎

However, if any of the values is a teen -- in the range 13-19 inclusive -- then that value counts as 0, except 15 and 16 do not count as a teens.

您在当前的解决方案中忘记了15和16(并且没有在其中使用第二个函数)。

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>>> def no_teen_sum(a, b, c):  # your solution
...     total = 0
...     for i in (a, b, c):
...         if i in range(13, 20):
...             x = 0
...         else:
...             x = 1
...         total += i*x
...     return total
...
>>> no_teen_sum(1, 2, 3) == 6
True
>>> no_teen_sum(2, 13, 1) == 3
True
>>> no_teen_sum(2, 1, 14) == 3
True
>>> no_teen_sum(2, 16, 1) == 19  # 16 doesn't count as 0
False

# Solution
>>> def no_teen_sum(a, b, c):
...     return sum(fix_teen(num) for num in (a, b, c))
...
...
... def fix_teen(n):
...     teens = {13, 14, 17, 18, 19}
...     return 0 if n in teens else n
...
>>> no_teen_sum(1, 2, 3) == 6
True
>>> no_teen_sum(2, 13, 1) == 3
True
>>> no_teen_sum(2, 1, 14) == 3
True
>>> no_teen_sum(2, 16, 1) == 19
True

简化版本：

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def no_teen_sum(a, b, c):
    result = 0
    for num in (a, b, c):
        result += fix_teen(num)
    return result


def fix_teen(n):
    if n in {13, 14, 17, 18, 19}:
        return 0
    else:
        return n


if __name__ == '__main__':
    assert no_teen_sum(1, 2, 3) == 6
    assert no_teen_sum(2, 13, 1) == 3
    assert no_teen_sum(2, 1, 14) == 3
    assert no_teen_sum(2, 16, 1) == 19
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