How to get the key from value in a dictionary in Python? [duplicate]

Answer 1

You can write a list comprehension to pull out the matching keys.

print([k for k,v in a.items() if v == b])

Answer 2

Something like this can do it:

for key, value in a.iteritems():
    if value == 10:
        print key

If you want to save the associated keys to a value in a list, you edit the above example as follows:

keys = []
for key, value in a.iteritems():
    if value == 10:
        print key
        keys.append(key)

You can also do that in a list comprehension as pointed out in an other answer.

b = 10 
keys = [key for key, value in a.iteritems() if value == b]

Note that in python 3, dict.items is equivalent to dict.iteritems in python 2, check this for more details: What is the difference between dict.items() and dict.iteritems()?