Set routines

Making proper sets

unique(ar[, return_index, return_inverse, …])

Find the unique elements of an array.

Boolean operations

in1d(ar1, ar2[, assume_unique, invert])	Test whether each element of a 1-D array is also present in a second array.
intersect1d(ar1, ar2[, assume_unique, …])	Find the intersection of two arrays.
isin(element, test_elements[, …])	Calculates element in test_elements, broadcasting over element only.
setdiff1d(ar1, ar2[, assume_unique])	Find the set difference of two arrays.
setxor1d(ar1, ar2[, assume_unique])	Find the set exclusive-or of two arrays.
union1d(ar1, ar2)	Find the union of two arrays.