Iterating over a dictionary's sorted keys

[Alan Daniels]

On 25 May 2000 08:56:38 GMT, Remco Gerlich
<scarblac-spamtrap at pino.selwerd.nl> wrote:

[snip...]
>Why the problem with multiple lines and an extra variable here and there?

Yes, but the short version reminds me very much of one of my favorite
python idioms:

    lines = open("some_file", "rt").readlines()

Grabbing lines out of a (reasonably small) file is something I do
quite often, and I love the simplicity and elegance of doing it all in
a very readable and succinct one-liner. Admittedly, I could always go
this route:

    f     = open("some_file", "rt")
    lines = []
    line  = f.readline()
    while (line):
        lines.append(line)
        line = f.readline()
    f.close()

But then that one-liner just became six-liner with two unneeded vars
left over. For that kind of wordiness, you may as well be writing in,
say, Java. :-)

The ability to do:

    for k in blah.keys().sort():
        print k

rather than:

    keys = blah.keys()
    keys.sort()
    for k in keys:
        print k

is only thwarted by the fact that the "sort()" method of a list
inexplicably returns a None. I truly wish that more methods returned a
reference to "self". After all, when you sort a list, don't you get a
new list, maybe not in implementation, but philisophically? Or when
you reverse it? Sure, its the same *object*, but its been changed. I
don't think returning a reference to itself would do any harm.

And then I could use one of the Java idioms I *do* like, the ability
to chain().method().calls().together() when they all operate on the
same object.

Java-Is-A-Harsh-Mistress'ly yours, Alan.

-- 
============================================================
Alan Daniels
daniels at mindspring.com