Set routines

Making proper sets

unique(ar[, return_index, return_inverse, ...])	Find the unique elements of an array.
unique_all(x)	Find the unique elements of an array, and counts, inverse, and indices.
unique_counts(x)	Find the unique elements and counts of an input array x.
unique_inverse(x)	Find the unique elements of x and indices to reconstruct x.
unique_values(x)	Returns the unique elements of an input array x.

Boolean operations

in1d(ar1, ar2[, assume_unique, invert, kind])	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.