confused about __str__ vs. __repr__

[Neal Becker]

Reading some FAQ, I see that __str__ is "meant for human eyes".

But it seems that:
class X(object):
    def __str__(self):
        return "str"
    def __repr__(self):
        return "repr"

x = X()
d = {0 : x}
print d
{0: repr}

So if __str__ is "meant for human eyes", then why isn't print using it!