使用Python字典值作为结果返回键

我不知道为什么这段代码在一些输入中失败（从CodingBat，链接到问题：）。下面是问题的详细信息，我可能可以使用

if elif

语句来回答这个问题，但我想使用字典。此外，我还了解到，不建议像下面使用的那样从字典中获取键值。但如果能指出以下节目中的问题，我将不胜感激

你开得有点太快了，一个警察拦住了你。编写代码计算结果，编码为int值：0=无票，1=小票，2=大票。如果速度小于等于60，则结果为0。如果速度介于61和80之间，则结果为1。如果速度大于等于81，则结果为2。除非是你的生日——在那天，你的速度在任何情况下都可以提高5

• 超速被抓（60，假）→ 0
• 超速驾驶被捕（65，假）→ 一,
• 超速驾驶被抓获（65，正确）→ 0

为……工作

caught_speeding(70, False)
caught_speeding(75, False)
caught_speeding(75, True)
caught_speeding(40, False)
caught_speeding(40, True)
caught_speeding(90, False)
caught_speeding(60, False)
caught_speeding(80, False)

---

看起来您混合了

Bir_dict

和

NoBir_dict

。你能试试下面的代码吗

def caught_speeding(speed, is_birthday):
        Bir_dict = {0:speed<=65,1:66<=speed<=85,2:speed>=86}
        NoBir_dict = {0:speed<=60,1:61<=speed<=80,2:speed>=81}
        def getKey(dict,value):
            return [key for key in dict.keys() if (dict[key] == value)]
        if is_birthday:
            out1=getKey(Bir_dict,True)
            return out1[0]
        else:
            out2=getKey(NoBir_dict,True)
            return out2[0]

---

难道这个问题不会考虑生日字典有更高的可用值吗？< /P> 如果是我的生日，我要65岁了： 我希望没有票。 但是，如果生成词典并打印它们，您可以看到情况并非如此：

def caught_speeding(speed, is_birthday):
    Bir_dict = {0:speed<=60,1:61<=speed<=80,2:speed>=81}
    print Bir_dict
    NoBir_dict = {0:speed<=65,1:66<=speed<=85,2:speed>=86}
    print NoBir_dict
    def getKey(dict,value):
        return [key for key in dict.keys() if (dict[key] == value)]
    if is_birthday:
        out1=getKey(Bir_dict,True)
        return out1[0]
    else:
        out2=getKey(NoBir_dict,True)
        return out2[0]

---

您只需将字典对象中的值交叉即可

Baa！非常感谢。我应该休息一下。感谢你的改进。

def caught_speeding(speed, is_birthday):
        Bir_dict = {0:speed<=65,1:66<=speed<=85,2:speed>=86}
        NoBir_dict = {0:speed<=60,1:61<=speed<=80,2:speed>=81}
        def getKey(dict,value):
            return [key for key in dict.keys() if (dict[key] == value)]
        if is_birthday:
            out1=getKey(Bir_dict,True)
            return out1[0]
        else:
            out2=getKey(NoBir_dict,True)
            return out2[0]

def caught_speeding(speed, is_birthday):
        Bir_dict = {0:speed<=65,1:66<=speed<=85,2:speed>=86}
        NoBir_dict = {0:speed<=60,1:61<=speed<=80,2:speed>=81}
        def getKey(dict):
            return [key for key in dict.keys() if (dict[key] == True)]
        if is_birthday:
            out1=getKey(Bir_dict)
            return out1[0]
        else:
            out2=getKey(NoBir_dict)
            return out2[0]

def caught_speeding(speed, is_birthday):
    Bir_dict = {0:speed<=60,1:61<=speed<=80,2:speed>=81}
    print Bir_dict
    NoBir_dict = {0:speed<=65,1:66<=speed<=85,2:speed>=86}
    print NoBir_dict
    def getKey(dict,value):
        return [key for key in dict.keys() if (dict[key] == value)]
    if is_birthday:
        out1=getKey(Bir_dict,True)
        return out1[0]
    else:
        out2=getKey(NoBir_dict,True)
        return out2[0]

{0: False, 1: True, 2: False}
{0: True, 1: False, 2: False}
0
{0: False, 1: True, 2: False}
{0: True, 1: False, 2: False}
1