Question

字典值是列表：

dictionary_1 = {"ABC": [1,2,3], "DEF":[4,5,6]}

如何从python中的5获取"DEF"的密钥，dictionary_1？

Answer 1

您可以创建反向字典：

>>> d = {i:k for k,v in dictionary_1.items() for i in v}
>>> d
{1: 'ABC', 2: 'ABC', 3: 'ABC', 4: 'DEF', 5: 'DEF', 6: 'DEF'}
>>> d[5]
'DEF'

Answer 2

也许是这样的？

my_value = 5
for k, v in dictionary_1.iteritems():
    if my_value in v:
        print k
        break
else:
    print "No key, defaulting to GHJ"

演示：

    In [12]: my_value = 8

    In [13]: for k, v in dictionary_1.iteritems():
        if my_value in v:
            print "Key for %s is %s" % (my_value, k)
            break
    else:
        print "No key found for %s, defaulting to GHJ" % my_value

    No key found for 8, defaulting to GHJ

Answer 3

你必须在字典中搜索：

try:
    key = next(k for k, v in dictionary_1.iteritems() if 5 in v)
except StopIteration:
    raise KeyError('Key for 5 not found')

这假设您正在寻找 a 键。要查找所有键，您可以使用列表推导：

keys = [k for k, v in dictionary_1.iteritems() if 5 in v]

列表可能为空。

Answer 4

一种方法是：

dictionary_1 = {"ABC": [1,2,3], "DEF":[4,5,6]}
for k, v in dictionary_1.items():
    if 5 in v:
        print(k)

Answer 5

假设你可以检查5是否在[4,5,6]列表中，你也可以尝试：

dictionary_1 = {"ABC": [1,2,3], "DEF":[4,5,6]}

print dictionary_1.keys()[dictionary_1.values().index([4,5,6])]

如何在python字典中获取值的键？

5 个答案: