Overloading "==" operator for numpy arrays

Question

I am defining a function in Python that needs to check

if a==b:
  do.stuff()

In principle, a and b could be numpy arrays or integers, and I would like my implementation to be robust against this. However, to check equality for a numpy array, one needs to append the boolean with all(), which will break the code when a and b are integers.

Is there a simple way to code the equality test so that it works regardless of whether a and b are integers or numpy arrays?

Sticking all on the comparison isn't even correct for arrays - you'll get a variety of false positives and exceptions when the arrays have mismatched shapes. — user2357112
– user2357112, Commented Apr 2, 2021 at 0:36
(Despite the exception message telling you to use any or all, using any or all is very rarely the right move when you get one of those exceptions. Usually the right move is something like numpy.where or numpy.array_equal.) — user2357112
– user2357112, Commented Apr 2, 2021 at 0:37

Ehsan · Accepted Answer · 2021-04-02 00:40:01Z

1

how about this that works for both arrays and integers(numbers):

if np.array_equal(a,b):
    do.stuff()

answered Apr 2, 2021 at 0:40

Ehsan

12.5k2 gold badges24 silver badges36 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Ehsan Over a year ago

@mikefallopian glad it helped.

hpaulj Over a year ago

Mike, you might find it instructive to look at the code for array_equal. It starts by turning the inputs into arrays. That's a common step in numpy functions.

Collectives™ on Stack Overflow

Overloading "==" operator for numpy arrays

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related