Common rows in multidimensional arrays in Python [duplicate]

Question

I have two numpy arrays or two pandas dataframes with three columns and different number of rows.

I want to find where the rows of the first array exist in the second array. Something like matlab's ismember function

[~, idx] = ismember(a, b, 'rows')

Is there a similar function in python? I do not want to use a loop.

Thank you for your answer but I do not want to merge the two dataframes. I want to find the indices where the two dataframes have equal rows. — gnikol
– gnikol, Commented Mar 19, 2018 at 20:08
you could still use merge and set the argument indicator=True and then sort by the _merge column. — ALollz
– ALollz, Commented Mar 19, 2018 at 20:28

Eelco Hoogendoorn · Accepted Answer · 2018-03-19 19:56:07Z

0

import numpy_indexed as npi
idx = npi.indices(a, b)

answered Mar 19, 2018 at 19:56

Eelco Hoogendoorn

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1 Comment

Is there a documentation for this package? Thank you.