Python : how can I impress people coming from Ruby/Java?

Question

I am preparing a presentation about Python for my company, and would like to show Python's awesomeness to developers using Java or Ruby ! I guess it will be very simple to write shorter and cleaner looking stuff than in Java, however I've never coded in Ruby (well only a few stuff with rails, but I don't know the language) !

PLEASE NOTE : This topic IS NOT about which language is the best. I just want to convince people that don't know Python at all, or even -for some- think that it is weird, that it is worthy of interest as well (as much as Ruby, Java, etc... are). And for this, I need input from people that know Ruby (or Java) and Python ...

I'm looking for an easy to understand code snippet or application that would shows where Python shines.

I was thinking of a couple of list comprehensions, because I think it is really great. Some operator overriding, because that looks dead simple in Python, maybe some metaclass programming, and/or why not a doctest/sphinx example ...

Any other/better suggestions ?

PS : the people are backend web developers

Answer 1

Build something (anything) from scratch at the python prompt.

It creates a compelling "story arc" from requirements to a completed script. It's helpful if it does something useful.

Avoid anything that looks like building a web site because the Ruby folks will compare your web demo head to head and feature to feature with Rails. And they'll always find one small thing that Rails does better than Django and that nuanced item with derail your presentation.

Pick something like log filtering. Or transforming a CSV file. Or using urllib2 to get something from the web and parse it.

Start with the Python >>> prompt and step through it, building up a script as you go.

Run the script as your closing flourish.

Answer 2

The concept of generators is something which is quite awesome in Python which I miss in the other languages (or at least I have a couple of drawbacks on their substitutes).

You may take any example from these great presentations [1, 2] and it'll even impress Python people.

Answer 3

As an ex-Ruby (and Java) programmer I found Python's SciPy and NumPy libraries very impressive.

I second the idea of showing list comprehensions, but I fear the Ruby crowd might not be impressed by Python metaclass programming.

Answer 4

A good swaggering should at least include:

• Duck Typing
• Pythonic for loops ('for each in seq:' instead of 'for i in range(0, len(seq)):')
• List Comprehensions / Generator Expressions
• Generator Functions
• itertools
• Functions as First Class Objects
• Higher Order Functions (decorators, functools)
• Metaclasses
• Batteres Included (std lib)
• import this
• numpy / scipy

Answer 5

I think you are looking at this from a wrong angle.

Language feature debates are esoterical

The presence of a language feature or the absence of another is not what makes a language useful. And even when your take a single feature, people might actually disagree on whether it is in fact an advantage or not. Personally - without wanting to argue, let alone claim I am right - I think the lack of static typing is a design flaw. I also think the static type system Java has serious design flaws. Same applies to operator overloading:

I saw `cout' being shifted "Hello world" times to the left and stopped right there.
— Steve Gonedes

There are countless religious wars fought about whether a language feature is good or bad. And in the end, there's probably no such thing as a good or bad feature. A feature can be well executed and compose well with all other language features. That's what makes a language elegant. Please note that elegant still doesn't mean useful, which is why I think you're looking at this from the wrong end.

Talk is cheap - code is code

To convince your counterpart, you will actually need to implement working solutions for a sufficiently realistic problem from the domain at hand. So will they. And than you will have to choose sensible metrics to compare both solutions. As for "Python vs Ruby", my guess as an outsider (I don't particularly care for either) is really, that you won't find much of a difference. There's claims that Django is faster than Rails. If you can actually prove that and if that speed difference is important, you might have a solid argument at hand. Other than that, I don't think any of you will be able to establish superiority of one language over the other. It'll just come down to a matter of taste.

Now as for comparing Python to Java, I think you should be able to plausibly demonstrate higher productivity with Python. But that's really for you to accomplish.

Either way, when comparing toolchains (which is what this is about in the end), any side of the argument must provide hard evidence on how their toolchain makes real life problems easier. Use that evidence to either prove that one toolchain is superior or toss a coin if all else fails. You either win by getting your way or win by getting a chance to learn something new.

Answer 6

One concrete feature to consider demonstrating is the ability to abstract out repetitive exception handling using the with statement and @contextlib.contextmanager.

Ruby can provide similar convenience through appropriate use of blocks, but Java doesn't have anything at all along these lines (short of adopting full-blown aspect-oriented programming)

Answer 7

a few weeks ago some friends of me started a small project. We had to choose between java and python. I used two key benefits to convince them of python:

• Lists. Python is famous for its incredible support for lists. In my opinion the fact that python is referred to as "working pseudocode" is because its list are so great. Show them the ease of creating a list, the treat of iterating with for and, lo and behold: LIST COMPREHENSIONS, they will love them

• Functions as "first class passengers". Especially java programmers will be yellow with envy at the prospect of parsing functions as parameters and lambda expressions. The sorted() function for lists is simply fantastic. In java you would have to create a function with an interface as a parameter and a custom class that implements the interface for any sorting algorithm.

Im afraid that your ruby colleages will probably remeain unmoved by this. After all python and ruby resemble each other in many aspects. Personally i would prefer python but thats a religious decision. Python or ruby is just a matter of taste. If you have to choose between them i would recommend a democratic vote. Youll be productive with both choices and this way you can avoid bad blood.

Answer 8

To evangelize to Java users, find some reasonably sized Java code and rewrite it using Jython. This gives python syntax using the Java libraries, and can show how Python can be both more terse and more clear than Java.