hacking and gonzo since 2000

Python vs. Ruby

There is a discussion on the net where people discuss Python vs. Ruby. The Ruby and Python Compared article started it, and here is a good answer article: Ruby misconceptions about Python.

I have both tried Python and Ruby and the languages are very alike, but yet a lot different. Python is more explicit - this gives clarity and more code.

An example of this clarity:

On Reddit a Ruby programmer posted some code that made building XML easy:

def method_missing(name, attributes)
  atts = attributes.map {|k,v| "#{k}='#{v}'" }.join(" ")
  puts "<#{name} #{atts}>"
  yield
  puts "</#{name}>"
end

With that special method one can do following:

div :id => "content" do
  a :href => "reddit.com" do
    print "reddit"
  end
end

I wrote something similar in Python:

import types
class Element:
  def __init__(self, **kw):
    self.elms = []
    self.kw = kw
  def __getattr__(self, name):
    if name == "__getitem__":
      self.elms = []
      def add(l):
        if type(l) == types.ListType: self.elms.extend(l)
        else: self.elms.append(l)
        return self
      return add
  def __str__(self):
    attrs = " ".join('%s="%s"' % a for a in self.kw.items())
    self.html = ["<%s %s>" % (self.name, attrs)]
    self.html.append("".join(map(str, self.elms)))
    self.html.append("</%s>" % self.name)
    return "".join(self.html)
class Div(Element): name = "div"
class A(Element): name = "a"

Where one can do:

print Div(id="content")[ A(href="reddit.com")["reddit"] ]

Functionality similar, but the way of achieving it is way different. Notice that in the Ruby case the "div" and "a" aren't defined and there is a lot of magic going on. In my Python code everything is defined explicitly. This approach gives a little more code, but better understanding. And that I think is the main difference between Python and Ruby.

Update

I have redone my Python version (functional style):

def elmBuilder(name, **kw):
  attrs = " ".join('%s="%s"' % a for a in kw.items())
  def applyElms(*elms):
    return "<%s %s>%s</%s>" % (name, attrs, "".join(elms), name)
  return applyElms
def Div(**kw): return elmBuilder("div", **kw)
def A(**kw): return elmBuilder("a", **kw)

One can then do:

print Div(id="content")( A(href="reddit.com")("reddit") )

My picnic in Lisp was well spent ;-)

Code · Python • 13. Apr 2006