Funny Python error messages

[Will Stuyvesant]

Add your funny or surprising Python error messages to this
thread.  A requirement is that you should also show
(minimal) code that produces the message.  Put the code
below, so people can think about how to generate the message
first, a little puzzle if you like.

Perhaps this will even be a useful thread, to brighten the
life of the brave people doing the hard work of providing us
with error messages.

My first one (i'm learning, i'm learning) is

TypeError: 'callable-iterator' object is not callable



#
#
#
#
# >>> it = iter(lambda:0, 0)
# >>> it()
# TypeError: 'callable-iterator' object is not callable