Delete array from array

Question

I want to delete elements from array A that may be found in array B.

For example:

A = numpy.array([1, 5, 17, 28, 5])
B = numpy.array([3, 5])
C = numpy.delete(A, B)

C= [1, 17, 28]

Answer 1

Numpy has a function for that :

numpy.setdiff1d(A, B)

That will give you a new array with the result you expect.

More info on the sciPy documentation

Answer 2

You can try :

list(set(A)-set(B))
#[1, 28, 17]

Or a list comprehension :

[a for a in A if a not in B]

Another solution :

import numpy 
A[~numpy.isin(A, B)]
#array([ 1, 17, 28])