Compare two 2D numpy arrays and remove rows

Question

I have two 2D numpy arrays

a = [[1,2,3], [3,4,5]] b = [[1,2,3], [3,4,5], [6,7,8]]

How do I do b-a as in remove rows in b that are found in a?

The answer I need is c = [[6,7,8]]

Thank you!

Answer 1

for i in range(len(a)):
   for j in range(len(b)):
       if(b[j] == a[i]):
           b.pop(j)

I think this should solve your problem.

Answer 2

You can use list comprehension here:

a = [[1,2,3], [3,4,5]] 
b = [[1,2,3], [3,4,5], [6,7,8]]

result = [x for x in b if x not in a]
print(result)

Output :

[[6, 7, 8]]