Python Speedup np.unique

Question

I am looking to speed up the following piece of code:

NNlist=[np.unique(i) for i in NNlist] 

where NNlist is a list of np.arrays with duplicated entries.

Thanks :)

Answer 1

numpy.unique is already pretty optimized, you're not likely to get get much of a speedup over what you already have unless you know something else about the underlying data. For example if the data is all small integers you might be able to use numpy.bincount or if the unique values in each of the arrays are mostly the same there might be some optimization that could be done over the whole list of arrays.