Getting up to date with Python
I haven’t paid much attention to what’s been happening to the Python Programming language since v2.3. Reading through the What’s New in Python 2.5 document, though, it looks like they’re rounding off a few more of the sharp edges - excellent. A couple of the syntax alterations will save me much code in future. All we need now are convenient anonymous functions, like what you get with function(args) { code } in Javascript, sub { code } in Perl, or { |args| code } in Ruby.
Some highlights:
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with foo(x) as bar: do_something(bar)callsbar.enter()before andbar.exit()after thedo_something(bar)call - similar to C#‘susingstatement.@contextlib.contextmanagerturns generators into classes, so foo(x) can be a function rather than a constructor. -
you can now send data back to an iterator with
it.send(value)(which otherwise behaves likeit.next()). -
try/except/else/finally can now be used together; no need to nest a try/except block inside a try/finally block.
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the fragile ‘a and b or c’ syntax now has a Perl/Ruby-like alternative: b if a
orelse c. (Thanks to Mike for the correction here) -
‘http://example.com/‘.partition(”://”) == (‘http’, ’://’, ‘example.com/‘)
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startswith/endswith now save you from looping in this common use case: ‘foo.jpg’.endswith((‘.jpg’, ‘png’, ‘.gif’))
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defaultdict is a dictionary that provides a default value when you don’t supply one. So now instead of mydict = {}; mydict.setdefault(key, []).append(value), you can use mydict = defaultdict(list); mydict[key].append(value)
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msilib lets you create MS Installer .msi files.
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ctypes, which lets you load DLLs / shared libraries and call arbitrary functions in them, is now in the standard distribution.
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ElementTree is now in the standard distribution, as xml.etree.
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new hashlib module: lots o’ hashes. md5, sha1, sha{224, 256, 384, 512}.
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sqlite3 is in the standard distribution!
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wsgiref, including basic http server, is now in the standard distribution!