Booleans question


#1

On Learn Python 12/14 I set age_is_12 to 0 which is false and then set name_is_maria as 1 which is true. The first exercise accepted 0 as false but the second exercise did not accept 1 as true, I had to type out “true”. Why is that?


#2

Please link to the exercise. Thanks.


#3

1 isn’t True, but True has the value 1 (bool inherits int, not the other way around)

One exercise might have tested truthyness (behaviour) and the other identity


#4

Exercise


#5

This illustrates the special relationship that 1 and 0 have with booleans.

print int(True)    # 1
print int(False)   # 0
print bool(1)      # True
print bool(0)      # False
print 1 == True    # True
print 0 == False   # True
print 2 == True    # False
print -1 == True   # False

Notice that only 1 and 0 are directly corresponding to True and False.

When we explore truthiness behavior we see how other values may be cast to a boolean…

print 2 and True   # True
print 0 and True   # 0

When 2 is cast to a boolean, its truthiness is evident because the expression yielded the second operand, meaning the whole thing is True.

When 0 is case to a boolean, its falsiness is evident because the expression yielded the first operand, meaning it was short-circuited by a False boolean, and the whole expression is False.


#6

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