And, oh by the way, Perl did it in exactly the same way that every other language with a built-in SORT verb did.

Actually, the sort function in Python 3 doesn't take a (two-arg) comparison function. It takes a (one-arg) key-generating function. Essentially, the Schwartzian transformation is built right in.

>>> x = ['c','B','a']
>>> x.sort(); print(x)
['B', 'a', 'c']
>>> x.sort(key=str.lower); print(x)
['a', 'B', 'c']
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(You can play games with operator overloading to get comparison-function behavior, but that's considered "unpythonic.")