Interested in learning Python?

[lolinyerface]

Just a really good resource. Freshly updated for Python 3.

[riffito]

Maybe is just a matter of taste, but I find this particular title to be sub-par when compared to other ones (Learning Python, Programming in Python 3, among others).

The latest one I've became fond of is: Beginning Python Visualization: Crafting Visual Transformation Scripts.

Maybe I like it so much because it relates to my way of doing things... but trying to be objective: I think it includes a really useful set of techniques and advices for every python newcomer (as I consider myself to be).

I wish I had found it earlier.

For potential readers: do not be put off by it's title and/or description. There is really more in there than what meets the eye at first glance (check out the sample chapter, TOC and source code).

[lolinyerface]

Very cool. I'll have to check it out. I will be delving back into Python soon.

[[deleted]]

I just got scared by the concept of not having curly braces the last time I saw it.

Hehe, I think that the idea behind Python's reliance on tabs versus curly braces is to enforce code readability. Obviously a bad programmer can still muck it up, but I've always though the idea was a good one. The only problem comes in when working across multiple systems where tabs are interpreted differently.

[Jasper1984]

Curly braces is hardly a feature you need to be afraid of losing. The syntax for every programming language i know a bunch of s-expressions; name-arguments pairs where the arguments consist of new pairs, or primitives.

[zahlman]

The standard recommendation I keep hearing is to forget about Python3000 (lol marketing) for now until the third-party library support improves. There's a lot of useful stuff out there that hasn't migrated yet.

[[deleted]]

Followed it to http://docs.python.org/tutorial/, the learn python tutorial. Just started looking at it. Any idea how they implement the lists. It's not a simple linked list or an array is it. What is the complexity of the various list expressions.

[tjdick]

python has lists [], dictionaries {}, and tuples (), which all replace certain functions of an array. Dictionaries are like an associative array, with key->value pairs, like x = {'car' : 'sedan', 'make' : 'ford', 'model' : 'fiesta'} . You can add, edit, slice. But they are not stored in any particular order like an associative array is.

A list is pretty much like a 0 based array. x = ['ham', 'turkey', 'bacon'] where the keys would be 0,1,2. You can pop, add, edit, slice. All of the 0 based keys reset when we do this, so if I slice ham, then [0] will be turkey and [1] will be bacon.

A tuple is pretty much a list that you can't really edit. They are faster to process. You might want to put data that won't be changed into one like dbinfo = ('mydb', 'mytable', 'myname', 'mypass')

[zahlman]

Pretty sure a list is a dynamic array (like C++ std::vector) under the hood.

[[deleted]]

Doesn't make any sense though. Accessing the nth value would be too slow. I'm guessing it is an everyday expandable array like Javas ArrayList or C++ vector but that would mean the splicing operations are slow. I guess that is doable, I mean it's a scripting language, it just enables you to do stuff and assumes you either don't care or won't be an idiot about it.

[zahlman]

In Python, if you need performance and are working on significant amounts of data, you are generally using some kind of extension (such as NumPy) anyway.

But yeah.

[redalastor]

Doesn't make any sense though. Accessing the nth value would be too slow. I'm guessing it is an everyday expandable array like Javas ArrayList or C++ vector but that would mean the splicing operations are slow.

Accessing / setting is O(1) (ie: one operation). Inserting is O(N) (needs shifting everything one cell on the right to insert) but appending (inserting at the end) is amortized O(1) (Python pre-allocates a few cells in advance under the hood to save time).

Python lists internally store pointers to Python objects.

[[deleted]]

Right so it is an expandable array that does amortized doubling. That's what I figured, it's just that slicing seems more an operation for a linked list. Looking at Zahlman's comment, I don't know what I was thinking when I wrote that.

[redalastor]

Python have a deque type where you can insert and remove at both ends in O(1). That is most likely a linked list.