True/False, NaN

print(True + 1) # 2, True and False are integers 
bool(True) # True
bool(None) # False
bool(0) # False
bool(0j) # False
bool(1) # True
bool([]) # False, empty collections “” [] tuple() dict() set()
bool([0]) # True

n = float('nan')
n == n            # False — violates reflexivity
n in [n]          # True!  — containment checks `is` before `==`
{n, n}            # one element, same reason
sorted([3, n, 1]) # garbage output — comparisons are all False

# bool is subinstance of int in python 

isinstance(True, int)      # True
True + True                # 2
sum([True, False, True])   # 2 — actually idiomatic for counting