Python @ PiTech - March 2009

PiTechnologies

Tudor Prodan
March 2009

What is Python

- a “very high-level language”
- developed by Guido van Rossum
- main features:

 simple, yet powerful semantics
 object-oriented, but multi-paradigm
 clean syntax and coherent design
 focus on productivity
 rich standard library
 lots of high quality 3rd-party
 several good implementations:
CPython, Pypy, IronPython (2.0.1), PyS60, Jython

Jython

Jython, lest you do not know of it, is the most
compelling weapon the Java platform has for its
survival into the 21st century :-)

—Sean McGrath, CTO, Propylon
July 31, 2003

CPython

Version history:
1.0 – Jan 1994
2.0 – Oct 2000
3.0 – Dec 2008

Latest stable versions:
2.6.1 and 3.0.1

Usable versions:
2.5.x
2.6.x = 2.5 + improvements + 3.0 features
(__future__)
| | |__ maintenance version
| |____ minor version
|______ major version

Why Python

 programming is fun again

Unfinished game

The problem of the unfinished game:

Let's say, hypothetically speaking,
you met someone who told you they had two children,
and one of them is a girl.

What are the odds that person has a boy and a girl?

-Jeff Atwood, December 30, 2008
http://www.codinghorror.com/blog

Unfinished game

LoC readable? fun?

Java 53 barely nope

C# 49 kind of not really

Python 10 clean, much more fun
concise than the above

Why Python

 agility
 elegance
 you don't have to fight the language

Why Python

Java is the COBOL of the 21st century.

-Sean Kelly, JPL, NASA

Spirit of C

Python is close to the “Spirit of C” (more than C++/
Java/...), as per ISO C Standard's “rationale”:

 trust the programmer
 don't prevent the programmer from doing what needs
to be done
 keep the language small and simple
 provide only one way to do an operation
 make it fast, even if it's not guaranteed to be
portable (the only bit not @100% in Python)

Python vs. C(++,#)/Java/..

 everything is a first-class object
- functions, methods, modules, ..

 typing: strong, but dynamic
- names have no type, objects have types

 no “declarations”, just statements
- implicit compilation, .pyc files
- everything is run-time (compile-time too)

 spare syntax, minimal ornamentation
- no { } for blocks
- no ( ) for conditions
- a lot less punctuation


In the 1960's the KGB was very interested in learning everything
possible about the American space program, sending all sorts of
spies to find every possible piece of information.

One afternoon, a breathless spy returned to headquarters with a
piece of paper in his hand, excitedly shouting to his superior,
"Comrade! Comrade! The Americans are using Lisp to write their
rocket launching software!“

The commander was skeptical. "How do you know?"

"I broke into their research lab and stole a page from the
teletype machine! It's not the whole program, but it's the final
page and contains the concluding logic of the program! See for
yourself!"

The commander looked at the page and smiled:


))))))))))))))))))))))))))))))))))))))))))))))))))))))
))))))))))))))))))))))))))))))))))))))))))))))))))))))
))))))))))))))))))))))))))))))))))))))))))))))))))))))
)))))))))))))))))))))))))))))))))))))))))
))))))))))))))))))))))))))))))))))))))
))))))))))))))))))))))))))))))))))))
)))))))))))))))))))))))))))
)))))))))))))))))))))))))
))))))))))))))))))))))
))))))))))))))))))))
))))))))))))))))
)))))))))))))))
)))))))))))
))))
)))
))
))
)

Why Python

Example #2:

Create a Coordinate class
which holds a latitude and longitude,
to be used by a TelemetryTracker object.

Why Python

this example will show
Python vs. Java

but is actually
Python vs. Java / C# / PHP / (most others)

Philosophy

You know you've reached perfection in design, not
when you have nothing more to add, but when you have
nothing more to take away.

-Antoine de Saint Exupery

Why Python

Java: Python:

Why Python

The Java guys will say:

 my IDE can generate most of that
- code is read a lot more than written

Why Python



 but, your fields are public
- Python philosophy

Why Python



 but, your fields are public
- Python philosophy

 can't we apply this to other languages?

Why Python

Eventually, the code will end up in production..

Java: Python:

Why Python

.. time passes ..

Eventually,
decodeLat receives bad data

This is a bug!

What do we do?

- add a check

Why Python

Add a setter and a getter:

Why Python

Add a setter and a getter:

Let's try it out:

Why Python

and the TelemetryTracker code:

Python:
- still works

Java:
- needs modification

Why Python

in the end:

Python:
- gives you a choice
- you can even change your mind

Java/C#/PHP/..:
- no choice

Why Python

 agility
 elegance
 the language trusts you
 .. it accommodates you

Why Python

 agility
 elegance
 .. and will not go out of it's way to stop you

Why Python

Python has
lots &
LOTS
of good
books:

Why Python

 agility
 elegance
 good documentation (lots of books)
 good support: lots of forums, mailing lists, IRC

Why Python

Large number of high quality 3rd-party libraries and
frameworks:

- networking: twisted, cogen, concurrence
- scientific: NumPy, ScyPy, PyEvolve (genetic algorithms)
- testing: PyUnit, Google Mox
- fuzzing: Fuzz
- database: SQLAlchemy, Elixir, Django ORM
- web crawling: BeautifulSoup, lxml, Scrappy
- game development: PyGame
- GUI: PyGTK, wxPython, PyQt, GTK#
-templating: Genshi, Mako, Kid, Jinja2
- cryptography: M2Crypto, PyCrypto, Keyczar,

.. many, many others

Why Python

 agility
 elegance
 good support: lots of forums, IRC, mailing lists
 lots of high quality 3rd-party libraries

Why Python

But most interesting to us,
lots of great web frameworks:

Why Python

 agility
 elegance
 good support: lots of forums, IRC, mailing lists
 lots of high quality 3rd-party libraries
 many great web frameworks

Python @ PiTech - March 2009

More Related Content

What's hot (20)

Viewers also liked (16)

Similar to Python @ PiTech - March 2009 (20)

Recently uploaded (20)

Python @ PiTech - March 2009