f---ing typechecking

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    >> Concatenating tuples and lists seems logical if you think of tuples
    >> as sequences.  If you think of them more like Pascal records or C
    >> structs instead (I believe that's Guido's perspective on tuples) then
    >> it makes no sense at all.

    James> Then iterating over them makes no sense?

I agree that tuples are a bit schizophrenic.  They really are sequences from
an implementation standpoint, but from a logical standpoint it's maybe best
not to think of them that way.

That said, this:

    for x in (1,2,3):
      pass

is a skosh faster (perhaps an immeasurably small skosh) than this:

    for x in [1,2,3]:
      pass

so people will probably continue to use tuples instead of lists in these
sorts of situations.

For an example of the struct-ness of a tuple consider the output of os.stat:

    >>> import os
    >>> s = os.stat("/etc/hosts")
    >>> s
    (33188, 34020475L, 234881029L, 1, 0, 0, 214L, 1170562950, 1124700602, 1142602578)
    >>> s.st_mtime
    1124700602.0
    >>> s[0]
    33188
    >>> type(s)
    <type 'posix.stat_result'>

It's effectively a tuple with field names.  I don't know when the switch
occurred (it's in 2.2, as far back as my built interpreter versions
currently go), but back in the day os.stat used to return a plain old tuple.

I have no idea if the schizophrenic personality of tuples will improve with
drugs^H^H^H^H^H Python 3, but I wouldn't be at all surprised if it did.

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