当键是由字符串表示的分数时，如何按值对dict进行排序？

Question

I need to sort a dict, where keys are fractions represented by strings and need to be sorted by its numerical values:

ie:

exp_time = {"2":10, "1/2":5:, "2.5":11, "1/200":9, "15":3, "1/30":6}

result should be like this(descending order):

15
2.5
2
1/2
1/30
1/200

Answer 1

>>> import fractions
>>> exp_time = {"2":10, "1/2":5, "2.5":11, "1/200":9, "15":3, "1/30":6}
>>> sorted(exp_time, key=fractions.Fraction, reverse=True)
['15', '2.5', '2', '1/2', '1/30', '1/200']