Implementing Tables In Python

Question

I'm using Google App Engine on a Udacity course online and this code is confusing me. I' haven't seen Python used this way. The Instructor doesn't go over NameTuple in the entire class so this was out of the blue for me. Can anyone explain how this code works and is there an easier why did Steve Huffman prefer this style of Python coding.

from collections import namedtuple

# make a basic Link class
Link = namedtuple('Link', ['id', 'submitter_id', 'submitted_time', 'votes',
                           'title', 'url'])

# list of Links to work with
links = [
    Link(0, 60398, 1334014208.0, 109,
         "C overtakes Java as the No. 1 programming language in the TIOBE index.",
         "http://pixelstech.net/article/index.php?id=1333969280"),
    Link(1, 60254, 1333962645.0, 891,
         "This explains why technical books are all ridiculously thick and overpriced",
         "http://prog21.dadgum.com/65.html"),
    Link(23, 62945, 1333894106.0, 351,
         "Learn Haskell Fast and Hard",
         "http://yannesposito.com/Scratch/en/blog/Haskell-the-Hard-Way/"),
    Link(2, 6084, 1333996166.0, 81,
         "Announcing Yesod 1.0- a robust, developer friendly, high performance web framework for Haskell",
         "http://www.yesodweb.com/blog/2012/04/announcing-yesod-1-0"),
    Link(3, 30305, 1333968061.0, 270,
         "TIL about the Lisp Curse",
         "http://www.winestockwebdesign.com/Essays/Lisp_Curse.html"),
    Link(4, 59008, 1334016506.0, 19,
         "The Downfall of Imperative Programming. Functional Programming and the Multicore Revolution",
         "http://fpcomplete.com/the-downfall-of-imperative-programming/"),
    Link(5, 8712, 1333993676.0, 26,
         "Open Source - Twitter Stock Market Game - ",
         "http://www.twitstreet.com/"),
    Link(6, 48626, 1333975127.0, 63,
         "First look: Qt 5 makes JavaScript a first-class citizen for app development",
         "http://arstechnica.com/business/news/2012/04/an-in-depth-look-at-qt-5-making-javascript-a-first-class-citizen-for-native-cross-platform-developme.ars"),
    Link(7, 30172, 1334017294.0, 5,
         "Benchmark of Dictionary Structures", "http://lh3lh3.users.sourceforge.net/udb.shtml"),
    Link(8, 678, 1334014446.0, 7,
         "If It's Not on Prod, It Doesn't Count: The Value of Frequent Releases",
         "http://bits.shutterstock.com/?p=165"),
    Link(9, 29168, 1334006443.0, 18,
         "Language proposal: dave",
         "http://davelang.github.com/"),
    Link(17, 48626, 1334020271.0, 1,
         "LispNYC and EmacsNYC meetup Tuesday Night: Large Scale Development with Elisp ",
         "http://www.meetup.com/LispNYC/events/47373722/"),
    Link(101, 62443, 1334018620.0, 4,
         "research!rsc: Zip Files All The Way Down",
         "http://research.swtch.com/zip"),
    Link(12, 10262, 1334018169.0, 5,
         "The Tyranny of the Diff",
         "http://michaelfeathers.typepad.com/michael_feathers_blog/2012/04/the-tyranny-of-the-diff.html"),
    Link(13, 20831, 1333996529.0, 14,
         "Understanding NIO.2 File Channels in Java 7",
         "http://java.dzone.com/articles/understanding-nio2-file"),
    Link(15, 62443, 1333900877.0, 1244,
         "Why vector icons don't work",
         "http://www.pushing-pixels.org/2011/11/04/about-those-vector-icons.html"),
    Link(14, 30650, 1334013659.0, 3,
         "Python - Getting Data Into Graphite - Code Examples",
         "http://coreygoldberg.blogspot.com/2012/04/python-getting-data-into-graphite-code.html"),
    Link(16, 15330, 1333985877.0, 9,
         "Mozilla: The Web as the Platform and The Kilimanjaro Event",
         "https://groups.google.com/forum/?fromgroups#!topic/mozilla.dev.planning/Y9v46wFeejA"),
    Link(18, 62443, 1333939389.0, 104,
         "github is making me feel stupid(er)",
         "http://www.serpentine.com/blog/2012/04/08/github-is-making-me-feel-stupider/"),
    Link(19, 6937, 1333949857.0, 39,
         "BitC Retrospective: The Issues with Type Classes",
         "http://www.bitc-lang.org/pipermail/bitc-dev/2012-April/003315.html"),
    Link(20, 51067, 1333974585.0, 14,
         "Object Oriented C: Class-like Structures",
         "http://cecilsunkure.blogspot.com/2012/04/object-oriented-c-class-like-structures.html"),
    Link(10, 23944, 1333943632.0, 188,
         "The LOVE game framework version 0.8.0 has been released - with GLSL shader support!",
         "https://love2d.org/forums/viewtopic.php?f=3&t=8750"),
    Link(22, 39191, 1334005674.0, 11,
         "An open letter to language designers: Please kill your sacred cows. (megarant)",
         "http://joshondesign.com/2012/03/09/open-letter-language-designers"),
    Link(21, 3777, 1333996565.0, 2,
         "Developers guide to Garage48 hackatron",
         "http://martingryner.com/developers-guide-to-garage48-hackatron/"),
    Link(24, 48626, 1333934004.0, 17,
         "An R programmer looks at Julia",
         "http://www.r-bloggers.com/an-r-programmer-looks-at-julia/")]


# links is a list of Link objects. Links have a handful of properties. For
# example, a Link's number of votes can be accessed by link.votes if "link" is a
# Link.

# make the function query() return the number of votes for the link whose ID is
# 15

def query():
    for l in links:
        if l.id == 15:
            return l.votes

print query()

Answer 1

namedtuple is used to create a basic struct-like object:

Link = namedtuple('Link', ['id', 'submitter_id', 'submitted_time', 'votes',
                       'title', 'url'])

…and use it like this:

some_link = Link(6, 48626, 1333975127.0, 63,
                 "Some title", "http://www.theurl.com")
print some_link.url
print some_link.id
.
.
.

Using this, you can create an object e.g. with the properties id, submitter_id etc. in a pretty easy way.

You could also do it with a class definition:

class Link(object):
    __init__(self, id, submitter_id, submitted_time, votes, title, url):
        self.id = id
        self.submitter_id = submitter_id
        self.submitted_time = submitted_time
        self.votes = votes
        self.title = title
        self.url = 

as you can see however, it is much more "complicated" ;-)

Answer 2

Here is a link to the Python docs for this function: http://docs.python.org/2/library/collections.html#collections.namedtuple.

The first paragraph gives some insight into why he would probably want to use this style:

Named tuples assign meaning to each position in a tuple and allow for more readable, self-documenting code. They can be used wherever regular tuples are used, and they add the ability to access fields by name instead of position index.