overriding bool() for custom class [duplicate]
Is this Python 2.x or Python 3.x? For Python 2.x you are looking to override __nonzero__ instead.
class test: def __nonzero__(self): return False
If you want to keep your code forward compatible with python3 you could do something like this
class test: def __bool__(self): return False __nonzero__=__bool__
If your test class is list-like, define __len__ and bool(myInstanceOfTest) will return True if there are 1+ items (non-empty list) and False if there are 0 items (empty list). This worked for me.
class MinPriorityQueue(object): def __init__(self, iterable): self.priorityQueue = heapq.heapify(iterable) def __len__(self): return len(self.priorityQueue)>>> bool(MinPriorityQueue([])False>>> bool(MinPriorityQueue([1,3,2])True