一下連結是我在stack overflow上的提問及解答，

https://stackoverflow.com/questions/53513792/python-dictionary-find-key-of-max-vlue/53515710#53515710

如對於字典d = {1:5， 2:0， 3:4, 4:0, 5:1}， 限定範圍k in [1, 2, 3] 或{1， 2， 3}正確解法如下：

Just get the keys and values for the keys 1, 2 and 3 in a list of tuples, sort the list and get the first tuple element [0]

d = {1: 5, 2: 0, 3: 4, 4: 0, 5: 1}
key_max_val = sorted([(k,v) for k,v in d.items() if k in [1,2,3]])[0][0]
print(key_max_val) # Outputs 1