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.
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.