Learning Python!

mrguyorama

So I am taking a Machine Learning class at University. In it we will be using python. Now, other than a quick (like hour long) stint with it back before I had any programming experience, I have avoided and disliked python for utterly silly and arbitrary reasons (whitespace as syntax? eww. Also I prefer explicit typing, in lieu of types being converted willy nilly and strange errors being silently swallowed by implicit conversions). However, I have to learn it and by golly, I take pride in my work. To that end, where is a good place to learn python? Good tutorials? And even more helpful, what is a simple project I could do in a few days to test my skill and learn me some python?

TL;DR I need to learn python, throw links at me

Warning: Python 3

ben_lubar

https://www.youtube.com/watch?v=8VSTzGwkMiM

mrguyorama

I... I'm sorry? I believe I have missed something.

...I haven't learned any python from that at all!

Kuro

This is ben. Don't worry, as long as he doesn't suggest a python tutorial written in dwarf fortress you are good.

How good are you in other languages?
Do you already have small projects in those languages you can simply rebuild in python? Ime that's usually pretty helpful because it showcases differences between the languages and does not require you to think about ~~boring~~ super interesting structure stuff that would be the same either way.

Filed under : Food for thought

edit : fixed for correct value

mrguyorama

I have significant (as in, actual experience in an enterprise and consumer facing industry application) experience with java, significant but untested experience with C, and at least a familiarity with many many other languages. I have a significant number of little programs written for different university classes that I could probably convert, and there's always project euler https://projecteuler.net/

@Kuro said:

boring structure stuff

BLASPHEMY!!! That is the LEAST boring kind of stuff

cartman82

This is the overall most highly regarded python book around:

Learn Python the Hard Way

Upsides:

It's doing a pretty good job at cheering you onward and motivating you to complete its stupid exercises
It's free

Downsides:

It's targeted at complete programming noobs.

Not a bad choice, but if you're an experienced programmer, you might get bored at some point.

The other thing I recently started doing is this:

CodingBat Python

It's mostly just a way to motivate myself to type in code, so I can hit my head against the wall and look shit up in documentation. I just started with this, so no strong recommendation from me yet.

mrguyorama

My one hour first look was with python the hard way. I didn't like how it focused so much on file I/O. Also isn't it for python 2.7? Either way, I guess the consensus is I just have to get off my bum and learn

jaming

@mrguyorama said:

what is a simple project I could do in a few days to test my skill and learn me some python?

I would suggest finding a problem you currently have and solving it with python. Think about what repetitive tasks you have that could be sped up with automation, perhaps. In my experience if you are not doing some contrived project, you will enjoy it more.

svieira

for knowing that your reasons are arbitrary

Given that you're coming from Java you'll want to read Python is not Java. The state of things isn't so disparate these days as it was then, but the cultures are pretty different. If you're looking at doing Machine Learning you'll want to look at Jupyter (or more specifically, ipython 4, which is the Python front-end for the tool), because it's a great way (so I'm told) to show your work. Depending on the kind of machine learning you are doing, you will probably also want to look at pandas as it makes all that IO that you want to abstract ... disappear.

As for a project - you might just want to dig through one of the smaller of the AWS public data sets and pull interesting facts out of it (I assume you are taking the Machine Learning class because you find such things interesting, not because you have to)

Things you probably already knew

pip + virtualenv is the closest thing Python has to maven / gradle / leiningen / sbt
Do your experiments in virtual environments - if you screw up the env, you just throw it away and try again, rather than having to un-break your system installation.

Python 3.5 is coming with optional type hints based on MyPy - it won't get you all the way back to the security of the compiler, but it does a pretty good job getting you 40% of the way.

Don't worry about willy-nilly conversions - that doesn't happen in Python. It's dynamically but strongly typed. 1 + "123" is a TypeError just as "123" + 1 is It still has gotchas, but they're of the "char is int " variety not the "Oh, but you had a leading zero in that string so I thought I should treat it as an octal number " of some languages.

dse

Considering you have specific application you want to learn in Python (Machine Learning) I suggest not to dive deep into Python-ish things like VirtualEnv, ... just start with Jupyter/iPython Qt Console, Scikit-Learn and Pylab/Matplotlib.

This is BTW what I do for living :)

loopback0

Python

powerlord

Given that you're coming from Java you'll want to read Python is not Java. The state of things isn't so disparate these days as it was then, but the cultures are pretty different.

Not to put too fine a point on it, but it reads like it was written by a Python person with only limited exposure to Java.

For example, this nugget:

Code duplication is quite often a necessary evil in Java, where you must often write the same method over and over with minor variations (usually because of static typing constraints).

Even back before generics were a thing in Java... well, @codinghorrorbot can tell you what I'd be doing if I did it this way.

Interfaces, for example. While you can't guarantee the existence of a variable in a class using them, you can guarantee a specific method exists... including a getter and/or setter. Interfaces have been in Java from the start. So, I can write interface Bar and write the signature for method Foo like this: public void Foo(Bar something) and voila, it doesn't matter which type I pass in as long as it implements Bar..

CodingHorrorBot

@‍powerlord Is Doing It Wrong™

dkf

@powerlord said:

Even back before generics were a thing in Java...

Let alone default methods…

powerlord

Default Methods didn't show up until last year and this article was written in 2004.

dkf

So? The article you're talking about is obviously even more obsolete than it was. :)

Lorne Kates

Why learn Python yourself when you can just hire the hottest tech talent?

[img]https://pbs.twimg.com/media/CNWrs6VUAAA0ZEm.jpg:large[/img]

Filed under: From the company that brought you Slashdot...

ben_lubar

https://www.youtube.com/watch?v=8bXSPfzW_sk

svieira

@powerlord said:

Code duplication is quite often a necessary evil in Java, where you must often write the same method over and over with minor variations (usually because of static typing constraints).

Even back before generics were a thing in Java...

I don't think he's talking about things which can be handled by generics. There are a lot of places where type classes or duck-typing would be used where your only choice in Java is a lot of boilerplate. At its simplest:

package third.party.one;

interface Thing1 {
  public String getMagic();
}

package third.party.two;

interface Thing2 {
  public String getMagic();
}

package third.party.three;

interface Thing3 {
  public String getMagic();
}

package your.namespace.here;

interface HandleThings {
    public String extractMagic(WHAT_TYPE_GOES_HERE anyThing);
}

sloosecannon

Err, I'm not sure I'm getting your example, care to exain further?

marczellm

I learned a lot about python by simply reading the official docs, specifically their tutorial. Not the whole thing though. But it's well written and structured.

dkf

If they're really coincident like that, you can do:

interface MixedThing extends Thing1,Thing2,Thing3 {}

and then just use that interface. You're not usually that lucky; it's more likely that one will want you to return an int, one a Double (because raisins) and one a String. Then you're stuck doing stupid adapters for everything.

presidentsdaughter

Funny enough, today I'll be givin a 4h crash course on Python to QA colleagues.

I have for them at the end of the session:

Python Courses & Tutorials | Codecademy

Start your coding journey with Python courses and tutorials. From basic to advanced projects, grow your Python skills at Codecademy.

Learn Python the Hard Way

Google's Python Class | Python Education | Google for Developers

Assorted educational materials provided by Google.

Learn Python - Free Interactive Python Tutorial

learnpython.org is a free interactive Python tutorial for people who want to learn Python, fast.

The code academy course is my favourite. Has a nice flow, in form of mini-projects, introducing new concepts as you advance.

abarker

@ben_lubar said:

https://www.youtube.com/watch?v=8VSTzGwkMiM

This is the Help area Ben. You are expected to be helpful, at least until the OP says that the requested help has been found.

mrguyorama

He did help me. He gave me a rough idea of how it feels when you run python for the first time and get yelled at for not having ":" in all the right places. un-C-like syntax is un-C-like