在python中，如何以重复的随机序列提取不同值的（最小）列表？

Question

In python , I have a scipy array (can also be just a list), which is a long random sequence of floats, but the possible values are just 4. I don't know which are those 4 values, and I need to find them. What would be the most efficient / elegant way to do that?

I have few ideas (sort the list, take the minimum, pop all the subsequent elements equal to that, take the first non-equal, etc.). Can you come up with something nicer?

Thanks!

Answer 1

You can use the builtin set function:

>>> ar = scipy.array([0.4,0.3,0.4,0.9,0.2,0.3,0.9,0.4,0.4])
>>> set(ar)
set([0.90000000000000002, 0.29999999999999999, 0.20000000000000001, 0.40000000000000002])