Question 1867

Which Keys Survive

d1 = {[1, 2]: "a"}
d2 = {(1, 2): "a"}
d3 = {(1, [2]): "a"}

Which of these three lines raise a TypeError?

A

None of them: Python only checks hashability on lookup, not on insertion

B

d1 and d3, but not d2

C

Only d1

D

All three, since dict keys must be tuples of immutable values