How do I distinguish a string from a sequence?

[Skip Montanaro]

    Paul> "Ability to be passed to popen2()" is what I'm after (at least in
    Paul> the initial version, later I might use fork/exec or low-level
    Paul> Win32 calls) and that isn't testable for...

Why not simply call popen2() with your argument and if it squawks, do
something about it?

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