I just hit the MSDN home page, and what should I see?
It’s cool to see JasonZ, aka my group’s general manager, blogging about our product.
I also fired up Visual Studio, and IronPython is the top headline there too:
Not sure why the news is dated September 18th, but hey it’s really cool to see IronPython (not to mention the DLR, with the second headline) getting this kind of visibility.
This is a very pretty sight. It’s a screenshot from the IronPython CodePlex home page showing that 2.0 is the “current release”. Yes that’s right, dear reader, IronPython 2.0 has officially been released!
This release marks the end of a very busy year for me, nine months to the day since I accepted the offer to join the dynamic languages team. Between helping ship IronPython 2.0 and helping manage the languages and tools PDC08 track, I’ve been swimming in the deep end of the pool all year. Feels good to not have any immediate deliverables for the next month or two.
Major, major props to Dino, IronCurt, Dave and Srivatsn who have done the heavy lifting on the IPy side this release. Also major props to the DLR team, who are releasing the final 0.9 version of the DLR later today in concert with IPy 2.0. (Update: the DLR 0.9 RTW bits are now available) And of course, HUGE HUGE HUGE thanks to the vibrant IPy community, many of whom are listed by name in the release notes.
Even with 2.0 finally out the door, there’s no rest for the dynamic. As per the release notes, “we’re planning on releasing IronPython 2.0.1 fairly soon” so keep those bug reports coming. Going forward, we’ve got big plans for IronPython and we rely heavily on the continued input from our community, so please keep telling us where we can improve.
On a personal note, the past nine months have been busy – very busy – but they’ve also been a blast. Frankly, I was hesitant about joining the product groups for a long time because I was worried about the grind, the culture, the overall experience. Turns out my fears were overblown, though I’m thinking that’s at least partially related to the fact that I work on a “little” project like IronPython rather than a huge project like Visual Studio.
Now that I have my list of Rock Band songs and I can get the right Zune metadata for most of them, I just need to write out the playlist XML. This is very straight forward to do with the classes in System.Xml.Linq.
def GenMediaElement(song): try: trackurl = zune_catalog_url + song.search_string trackfeed = XDocument.Load(trackurl) trackentry = First(trackfeed.Descendants(atomns+'entry')) trk = ScrapeEntry(trackentry) return XElement('media', (XAttribute(key, trk[key]) for key in trk)) except: print "FAILED", song zpl = XElement("smil", XElement("head", XElement("title", "Rock Band Generated Playlist")), XElement("body", XElement("seq", (GenMediaElement(song) for song in songs)))) settings = XmlWriterSettings() settings.Indent = True settings.Encoding = Encoding.UTF8 with XmlWriter.Create("rockband.zpl", settings) as xtw: zpl.WriteTo(xtw)
XElement’s constructor takes a name (XName to be precise) and any number of child objects. These child objects can be XML nodes (aka XObjects) or simple content objects like strings or numbers. If you pass an IEnumerable, the XElement constructor will iterate the collection and add all the items as children of the element. If you’ve had the displeasure of building an XML tree using the DOM, you’ll really appreciate XElements’s fluent interface. I was worried that Python’s significant whitespace would force me to put all the nested XElements on a single line, but luckily Python doesn’t treat whitespace inside parenthesis as significant.
Creating collections in Python is even easier than it is in C#. Python’s supports a yield keyword which is basically the equivalent of C#’s yield return. However, Python also supports list comprehensions (known as generator expressions), which are similar to F#’s sequence expressions. These are nice because you can specify a collection in a single line, rather than having to create a separate function, which is what you have to do to use yield. I have two generator expressions: (XAttribute(key, trk[key]) for key in trk) creates a collection of XAttributes, one for every item in the trk dictionary and (GenMediaElement(song) for song in songs) which generates a collection of XElements, one for every song in the song collection.
Once I’ve finished building the playlist XML, I need to write it out to a file. Originally, I used Python’s built in open function, but the playlist file had to be UTF-8 because of band names like Mötley Crüe. Zune’s software appears to always use UTF-8. In addition to setting the encoding, I also specify to use indentation, so the resulting file is somewhat readable by humans.
The playlist works great in the Zune software, but since it’s a streaming playlist there’s no easy way to automatically download all the songs and sync them to your Zune device. I expected to be able to right click on the playlist and select “download all”, but there’s no such option. Zune does have a concept called Channels where the songs from a regularly updated feed are downloaded locally and synced to the device. However, the Zune software appears to be hardcoded to only download channels from the catalog service so I couldn’t tap into that. If anyone knows how to sign up to become a Zune partner channel, please drop me a line.
Otherwise, that’s So there you have it. As usual, I’ve stuck the code up on my SkyDrive. If I can remember, I’ll try and run the script once a week and upload the new playlist to my SkyDrive as well.