I can't think of a reason why the code beneath this text wouldn't work, however, for some reason, Codecademy keeps giving me an error message. The error message is:
File "python", line 3
SyntaxError: can't assign to operator
I'm certain that this code should define replacement, and then add replacement into the list in the place of the second item (or first, based on how Python looks at items in lists).
def list_function(x): return x x + 3 = replacement x = replacement n = [3, 5, 7] print list_function(n)