difference between 2 arrays

[Pierre]

Hello,

I would like to know how to find the difference (set operation)
between 2 arrays :

a = array([1,2, 3,2,5,2])
b = array([1,2])
I want a - b = [3,5]

Well, the equivalence of setdiff in matlab...

I thought a.difference(b) could work, but no : AttributeError:
'numpy.ndarray' object has no attribute 'difference'

Thanks !