James Denton

1

• James Denton
• COSC 4153
• Spring 2008
• Assignment 11

2
Overview

• History
• Syntax and Semantics
• Example Code
• Use of the Language in Industry
• Advantages and Disadvantages
• Likes and Dislikes

3
Brief History

• Created by Gudio van Rossum in 1991
• Initially borrowed ideas from Modula-3 and LISP
• Supported lambda calculus, map, filter, and
  reduce, among other things.
• Python 2.0 list comprehensions and garbage
  collection
• Python 2.2 unified types (Object oriented)?
• Python 3.0 will address design flaws, reduce
  feature duplication, and break backwards
  compatibility

4
Basic Syntax and Semantics

• Indentation used to mark statement blocks.
• for loop cycles through lists, not numbers. (for
  item in list)?
• if true
• do this
• def used to declare functions

5
Example Source Code

• Boring Hello World example.
• print I'm not dead yet!
• More interesting example.
• gtgtgt for row in range(1, 11)
• ... for col in range(1, 11)
• ... print "3d " (row col),
• ... print
• 1 2 3 4 5 6 7 8 9 10
• 2 4 6 8 10 12 14 16 18 20
• 3 6 9 12 15 18 21 24 27 30
• 4 8 12 16 20 24 28 32 36 40
• 5 10 15 20 25 30 35 40 45 50
• 6 12 18 24 30 36 42 48 54 60
• 7 14 21 28 35 42 49 56 63 70
• 8 16 24 32 40 48 56 64 72 80
• 9 18 27 36 45 54 63 72 81 90
• 10 20 30 40 50 60 70 80 90 100

6
More code

• gtgtgt breakfast "spam,spam,eggs,spam,and ham"
• gtgtgt order ""
• gtgtgt for item in breakfast.split(',')
• ... if item "spam"
• ... order (item " ") 3
• ... else
• ... order item " "
• ... print b
• Output
• spam spam spam
• spam spam spam spam spam spam
• spam spam spam spam spam spam eggs
• spam spam spam spam spam spam eggs spam spam spam
  
• spam spam spam spam spam spam eggs spam spam spam
  and ham

7
Use of the Language in Industry

• As Glue
• Industrial Light and Magic
• Glues together several separate rendering tools.
• Used for plugins and extensions for rendering
  tools.
• Rapid development
• NASA - Used in custom workflow automation
  software.
• YouTube
• First BitTorrent client
• Amazing string manipulation support
• Google

8
Advantages and Disadvantages

• Advantages
• Scales well
• Exceptions with safe error checking
• Dynamic typing
• Handles strings extremely well
• Pseudocode-like syntax - very readable and clean
• Fast prototyping
• Interfacing with C is easy
• Python has been ported to everything
• Easily interfaces with C code and libraries
• Disadvantages
• It's interpreted
• Closed source Python program? What's that?
• Can easily be decompiled. Only reliable way is to
  run as a server-side application.
• Performance
• Slow algorithms are typically programmed in a
  lower level language like C, which Python than
  interfaces with

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Likes and Dislikes

• Likes
• Excellent first language
• It supports several different paradigms
• object oriented and structured fully supported
• Also possible to use as a functional or
  aspect-oriented language
• Tons of libraries
• Dislikes
• One true way to code The Right Way
• Error your tab hath not enough spaces
• Can't really compile your code into a stand-alone
  binary like in C.
• The type system is great, but confused me at
  first.

10
Conclusion

• Easy to learn interpreted scripting language
• Good for interfacing with other languages,
  prototyping things quickly, and working with
  strings.
• Strongly typed, but does not enforce static
  typing.
• It turned me into a newt!
• I got better.

11
Bibliography

• IBM Developer Works
• http//www.ibm.com/developerworks/opensource/libra
  ry/os-python6/
• Wikipedia
• http//en.wikipedia.org/wiki/Python_(programming_l
  anguage
• Python.org
• http//www.python.org/
• Using Linux in the real world python server
• http//www.luv.asn.au/overheads/realworld/server.h
  tml
• A Gentle Introduction To Python
• http//spinning-yarns.org/michael/misc/python-intr
  o.pdf