Ruby and Python: perspectives

micampe — Fri, 10 Nov 2006 07:03:00 -0800

I just realized something interesting.

In Ruby you mix in modules that add methods to objects that implement interfaces.

In Python you have functions that you use on objects that implement interfaces.

One easy example are enumerables/iterables: in Ruby, an object is enumerable if it implements the each method. The object can then mix in Enumerable to gain some methods that you can use:

f = File.new(".bashrc", "r")
lines = f.find_all { |l| l =~ /^[^#]/ }
# or lines = f.grep(/^[^#]/)

In Python, an object is iterable if it implements the __iter__ method, and the language “knows” how to use the iterators:

f = file(".bashrc", "r")
lines = [ l for l in f if not l.startswith("#") ]
# or lines = filter(lambda l: not l.startswith("#"), f)

other examples are any and all, which incidentally are what started the discussion with Francesco about this:

In Ruby, the any? method is added to every enumerable object that mixes in Enumerable:

lines.any? { |l| l =~ /^#/ }

In Python, any() is a built-in function (introduced in 2.5) which knows how to use any sequence:

any(l.startswith("#") for l in lines)

So Ruby works from the inside, and Python from the outside of objects. I think therefore that the next comparison between the two languages should not be side-by-side, but inside-and-out.

Ops, I did it again

micampe — Tue, 05 Apr 2005 10:21:00 -0700

Yes, I changed the style again. The old one got me tired pretty soon – I was missing the green! – so I changed it. I’ve gone for even more simplicty and minimalism this time.

I’m not entirely satisfied with the orange rollover on the menu and I’d like some cool header image, but for now I’m keeping it as it is.

Someone liked the old design very much so it will probably come to a new life soon in some other form.

Michele Campeotto: Tag style

Ruby and Python: perspectives

Ops, I did it again