Admittedly I’ve been caught in the community currents moving towards Ruby and Rails development triggered by the Pragmatic Programmers. While on the ride I’ve been weary of their seemingly direct competitors, Python and Django.
The choice of which to use has usually been an emotion charged debate.

While others have poked around and performing comparisons, I thought I’d take a quick look for myself.
There are two comparisons at play here which I’ll split into two entries: Python vs. Ruby, Django vs. Rails.

Here’s my take on Python vs. Ruby. Granted it’s a long way off comprehensive, biased by my knowledge of Ruby.

Ruby

Pro’s

• Everything is an object
• Method discovery built into the language
• Language reads more naturally, take optional parenthesis as an example
• ! and ? methods suffixes are a nice standard for communicating intent
• return optional
• More object focused
• Often more readable
• IntelliJ IDE support

Con’s

• Slower
• Less Mature

Python

Pro’s

• Blocks via indentation more terse
• Class methods can be easily treated as function objects
• No need for @, @@, $ as namespaces are used
• Method arguments can be passed by name
• Automatically generates compiled scripts for efficiency

Con’s

• pass required for empty blocks
• Parenthesis required on method calls
• self required as first argument to methods
• return required
• Verbose import statements, e.g. from package.subpackage.module import class, class.method.
• Why import an individual method or variable?!
• Is from datetime import datetime DRY?!
• Less object focused, attributes are also first class citizens
• Method documentation (docstring) within method doesn’t aid readability
• Method default values are only evaluated once and reused in subsequent calls
• Non-OO approach to sequence manipulation and list comprehensions with methods such as map, del, sort and sorted
• Dictionaries throw an exception when key not found
• No concept of scope, class internals completely exposed. Use convention (such as underscore prefix) to suggest scope
• Ruby has Rake and Python has ?!

Weird stuff

• zip is an unusual name for iterating over multiple sequences
• Comparison chaining is unorthodox, i.e. 1 < 2 == 2
• ‘Isn’t’ produces the string “Isn’t”. However ‘Isn’t”‘ produces the string ‘Isn’t”‘. In the latter case a backslash remains and the start and end quotes are different.

Similarities

• The languages feel remarkably similar. They both seem as terse.
• Gem’s and Egg’s
• JRuby and Jython
• IronRuby and IronPython

Other discussions of Ruby vs. Python:

• Python up, Ruby down: If that runtime don’t work, then its bound to drizzown
• Should I Learn Python or Ruby next?
• Ruby, Python, “Power”
• Ruby vs Python - it’s a pointless argument

REST fundamentals

HTTP supports 4 request (method) types:

• Post: Intended to create a resource
• Get: Intended to retrieve a resource
• Put: Intended to update a resource
• Delete: Intended to delete a resource

However browsers typically only support Post and Get requests. Put and Delete requests have been ignored and fulfilled by abusing Post and Get. The essence of REST lies in considering the web as providing information about resources, it proposes to change the way we view URL’s from actions to requests on a resource. Actions that were once part of the URL (i.e. /products/show/1), are now expressed in the method (HTTP GET /products/1).

Why should I use REST?

The key reasons appear to be:

• As an alternative to Web Services, Messaging etc. for manipulating a resource
• A consistent approach to resource discovery

Also consider that the cost of implementing RESTful requests in Rails is no more than conventional requests.

Rails Support

Rails accommodates the lack of browser support for Put and Delete with an additional request parameter that simulates the request type.

routes.rb is the key

The core of Rails’ REST support lies in routes.rb. As always, entries here map URL’s to controllers and actions.
The following entry allows the Product model to be accessed as a RESTful resource.

map.resources :products

These entries also generate methods used to assemble URL’s in views and controllers. Based on the previous example the following methods are generated:

• products_url, products_path
• product_url(id|product), product_path(id|product)
• new_product_url, new_product_path
• edit_product_url(id|product), edit_product_path(id|product)

They can be used as follows:

• Link to list all Products

  link_to 'Products', products_path

• Form for creating a new product

  form_tag(:product, :url => products_path) do

• Form for editing a product

  form_tag(:product, :url => product_path(@product), :html => {:method => :put}) do

• Link to delete a Product

  link_to 'Delete', product_path(@product), :method => :delete

• Performing a redirect to view a Product

  redirect_to product_url(@product)

Controllers respond via respond_to

REST allows clients to request different response types. Controller actions accommodate this using respond_to. Example:

def show
  all_product = Products.find :all
  respond_to do |format|
    format.html
    format.xml render(:xml => all_products.to_xml)
  end
end

To issue a non-HTML RESTful request the URL must be a RESTful URL ending with .<desired type>. For example a XML request should end in .xml (i.e. METHOD GET /products/1.xml).

Scaffold support

Rails scaffolding supports the use of REST:

rake scripts/generate scaffold_resource <name> <field>:<type> <field>:<type>...

This command

• Creates: model, restful controller, views, migration with columns
• Edits: routes.rb for RESTful request support

I’ve traditionally installed Ruby, RubyGems and Rails via installers. Far a laugh, I thought I’d try it from binaries but I found the experience a bit rough on the edges.
Here’s some problems I encountered with workarounds - if anyone has nicer alternatives drop me a line.

RubyGems install: No such file to load — ubygems (LoadError)

To install RubyGems it’s recommended to execute

ruby setup.rb

after extracting the gems archive (more details can be found here).
First time I tried this I encountered this problem. Turns out the cause of this was some legacy environment variables lying around from an old install, as detailed here. So I removed RUBYOPT and tried again.

RubyGems install: zlib.dll not found

Second time I executed ruby setup.rb this problem surfaced. I downloaded the dll via zlib.net, renamed the dll from zlib1.dll to zlib.dll, placed it in the ruby/bin directory and tried again.
Viola! Success! RubyGems setup complete.

Rails install: Could not find rails (> 0) in any repository

When attempting to install rails I received this error. Google told me this was the most common solution, but the last comment was the winner.
Run gem install rails -y the second time and you’re done.

Rails console startup: readline.dll not found

Yet another dll missing! On this occasion Google said download the readline package for windows and do the right things with the dll.
Viola!

For what it’s worth I can handle the first problem, but the others seem a tad unnecessary.