ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

Question

I just discovered a logical bug in my code which was causing all sorts of problems. I was inadvertently doing a bitwise AND instead of a logical AND

Answer 1

This typed error-message also shows while an if-statement comparison is done where there is an array and for example a bool or int. See for example:

... code snippet ...

if dataset == bool:
    ....

... code snippet ...

This clause has dataset as array and bool is euhm the "open door"... True or False.

In case the function is wrapped within a try-statement you will receive with except Exception as error: the message without its error-type:

The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()