dtype='| 'in [ ]ints np array([ ]in [ ]np unique(intsout[ ]array([ ]contrast np unique with the pure python alternativein [ ]sorted(set(names)out[ ]['bob''joe''will'another functionnp in dtests membership of the values in one array in anotherreturning boolean arrayin [ ]values np array([ ]in [ ]np in (values[ ]out[ ]array(truefalsefalsetruetruefalsetrue]dtype=boolsee table - for listing of set functions in numpy table - array set operations method description unique(xcompute the sortedunique elements in intersect (xycompute the sortedcommon elements in and union (xycompute the sorted union of elements in (xycompute boolean array indicating whether each element of is contained in setdiff (xyset differenceelements in that are not in setxor (xyset symmetric differenceselements that are in either of the arraysbut not both file input and output with arrays numpy is able to save and load data to and from disk either in text or binary format in later you will learn about tools in pandas for reading tabular data into memory storing arrays on disk in binary format np save and np load are the two workhorse functions for efficiently saving and loading array data on disk arrays are saved by default in an uncompressed raw binary format with file extension npy in [ ]arr np arange( in [ ]np save('some_array'arrfile input and output with arrays www it-ebooks info