python - Adding 1 to a set containing True does not work -

i have started learn python , have encountered little strange when playing sets. following code sample doesn't produce expected results.

a_set = {true,2,3,4} a_set.add(1) 

i expected a_set have values {true, 1, 2, 3, 4} instead code produced {true, 2, 3, 4}.

trying variations on produced same results:

a_set = {1,2,3,4} a_set.add(true) 

expected {true, 1, 2, 3, 4} actual {1, 2, 3, 4}

trying false , 0 obtained same results:

a_set = {false,2,3,4} a_set.add(0) 

expected {false, 0, 2, 3, 4} actual {false, 2, 3, 4}

a_set = {0,2,3,4} a_set.add(false) 

expected {false, 0, 2, 3, 4} actual {0, 2, 3, 4}

i understand bool type inherited int , true == 1 , false == 0 still little surprised above results.

does know if behaviour design? possible have set contains both true, false, 0, , 1?

i did perform quite bit of googling not able find answer questions.

thanks in advance

update

in response comments below agree following question partially answers question.

is false == 0 , true == 1 in python implementation detail or guaranteed language?

but feel doesn't answer query have regarding behaviour of sets , whether possible have set containing both true , 1. though bool inherited int, different types, found fact set cannot distinguish between true , 1 little confusing. question behaviour of sets in python not true == 1.

for historical (hysterical?) reasons python's bool type subclass of int, , true equal 1 , false equal 0.

they hash same location well:

>>> true == 1 true >>> hash(true) == hash(1) true >>> false == 0 true >>> hash(false) == hash(0) true 

since both true , 1 considered equal , hash same slot, both set , dict treat them same thing.

you'll see same dictionary:

>>> true in {1: 'foo'} true >>> 1 in {true: 'foo'} true 

this behaviour extends other numbers too; floating point values equal integer values show same behaviour:

>>> {1.0, 1, 2.0, 2} {1, 2} 

but @ least reasons why happens little more.. obvious.