You can use the below-mentioned code in Python 2.x this will print george which is the key in our dictionary:-
mydict = {'george':16,'amber':19}
print mydict.keys()[mydict.values().index(16)]
If you are using Python 3.x you need to do as follows:
mydict = {'george':16,'amber':19} print(list(mydict.keys())[list(mydict.values()).index(16)])
Basically what it does is, it separates the dictionary's values in a list, finds the position of the value you have, and gets the key at that position.