How to sort a list? NOT a newbie question.

[Skip Montanaro]

    Michael> For the particular problem I was working on, it was simple to
    Michael> find a workaround that was only slightly awkward.  I don't have
    Michael> any idea how to address the case shown above.  Admittedly, it
    Michael> is largely a rhetorical question, but what do people think is
    Michael> the "one obvious way" to sort such a list?  The goal is an
    Michael> "arbitrary but deterministic" sort, much like with other
    Michael> heterogeneous lists.

Seems to me that you need to convert complex numbers to reals for
comparison.  That can be done a number of ways.  Some that come immediately
to mind include:

    * compare them as tuples, e.g., compare 1+2j as (1,2)
    * ignore either the real or imaginary part
    * compare them using magnitudes

Which you choose will depend on your application.

Here's an example of ignoring the imaginary part:

    def _cmp(x,y):
        if hasattr(x, "real"):
            x = x.real
        if hasattr(y, "real"):
            y = y.real
        return cmp(x,y)

    l2 = [1, 1j, [1,'1j']]
    l2.sort(_cmp)
    print l2

-- 
Skip Montanaro (skip at pobox.com)
http://www.mojam.com/
http://www.musi-cal.com/