Question

I have this array

     a = array([1,5,7])

I apply the where function

     where(a==8)

What is returned in this case is

    (array([], dtype=int64),)

However I would like the code to return the integer “0” whenever the where function returns an empty array. Is that possible?

Answer 1

def where0(vec):
    a = where(vec)
    return a if a[0] else 0
    # The return above is equivalent to:
    # if len(a[0]) == 0:
    #     return 0  # or whatever you like
    # else:
    #     return a

a = array([1,5,7])
print where0(a==8)

And consider also the comment from aix under your question. Instead of fixing where(), fix your algorithm