Firstly there are different versions of python, second not all implementations have the same build in methods.
If you want cross platform you need to have the packages and then export them in your distribution. The course can be any of the 2.7 series of python, also some of the builtins are blocked from use.
Personally I would just use the regex module for this.
from re import sub
return sub(r"[aeiouAEIOU]", '', input_)
The above takes an argument, then it takes what it will replace it with, and finally the string to work on.
The letters in the bracket means that for each item of any of them match the bracketed items it will sub that position.