Yes, you should program in Python! (or a similar agile language) :-)

My main points:

  - Python is excellent for refactoring (beats C++ and, yes, Java too)
  - Don't move an inch with unit and system tests
  - These tests are much easier to write in Python
  - Compiler-checked interfaces aren't that important
  - After a few serious successes, Python is a very serious contender in
  my company.

Now to our application's story:
We ported a large application core to Python (original was in C++ - we wrote
it too).
Our motivation was maintainability - we were sure we could reduce that
hulking core to a smaller and simpler creature. This really did happen, to
the point that the project never went into maintenance mode - it suddenly
became useful for things we didn't predict :)

We got performance benefits as well (yes, we were surprised). The reasons
were straightforward - we had many more options when refactoring the code,
and separated a lot of logic neatly (for example extracted DB caching to a
decorator - "AOP" in a language that needs a new term :-)

The gains we ended up getting could have been achieved in C++, obviously,
but they only became apparent after refactoring with Python.

We also wrote a quick sample client/server application with Twisted, which
was later modified in 2 weeks by someone different and transformed into an
excellent production application, that's still working flawlessly after 6
months with no maintenance. All this with about 300 lines of simple,
practically stupid, "I understand this code the first time I see it" code
(actually, this is probably the reason for the quality).

Now, every time someone says "client/server" people think about Python and
Twisted, and even a large legacy network client is being replaced with a
small Twisted client soon.

How come Python is so amazing for refactoring?
First, you need really good tests. I don't miss the compiler when I have
really good tests.
The good side is that to develop at good quality and speed you need really
good tests in any language, so you're not losing anything.
These tests are also so much easier to write in Python - we get more and
better tests, and spend less time writing them. (Whatever language you use
for the system, you should probably test in a language like Python).

Once these tests are in place, refactoring in Python with a good text editor
and some basic tools is so much smoother than C++ or Java, even with
Eclipse's really cool 'Refactor' menu.
Those actions that are trivial in Eclipse ( e.g. 'Rename Method') are a
little more complicated in Python, but not by much (remember the good
On the other hand, anything that isn't in Eclipse's context menu is
absolutely horrible to do in Java, to the point that I've met many good Java
developers that don't think anything else exists at all :) In Python, I've
found it to be a snap.
And when you add all the more and less dynamic tools that can be put to good
use, I'm one happy refactorer. Decorators, bound methods, generator
expressions, and the like give me many ways to make the code simpler that
aren't nearly as accessible in Java (or barely possible in C++).

Why aren't interfaces that important? The reason I like interfaces is as
documentation that the compiler happens to check. It's convenient, but I
don't terribly miss it in the presence of (a) good documentation, and (b),
you guessed it, good tests :-D
I don't have much experience with zope.interface, so I don't know how easy
it is to use or how much of the benefit from interfaces you get.
I must say about this point that I'm comparing a full static-typing approach
(e.g. Java) to a full dynamic-typing approach (e.g. Python) - give me
dynamic typing any day. A hybrid statically- and dynamically-typed language
like Groovy could work better, I don't have the experience to say.


On 4/16/07, Ronnie Maor < [EMAIL PROTECTED]> wrote:

I just joined a new startup and trying to build a case for using python as
the main programming language. Performance shouldn't be a problem for this
application, and the main considerations are quick development cycle and
It would really help if I could give examples of companies that use python
as a significant part of their main application / business logic.
Can anyone give such examples? preferably from your companies, other
israeli companies you know, or well known and successful non-israeli

Omri Reuter - does python play such a role in egloo or is it a glue for
logic in another language?
Ori Peleg - IIRC you mentioned rewriting the ORM for your company in

Another thing:
Before I raised the python idea, the leading thoughts were C# (windows
dependency isn't a problem). My thoughts were on using IronPython with C#
(for extensions, and using .NET libraries), and I think python would be more
powerful as the framework language, with C# in specific areas instead of the
other way around.
One risk is that IronPytnon is relatively new. Anyone have experience with
it? know how stable it is?
anyone think using IronPython or python in general for such a purpose is a
bad idea?

your comments much appreciated