Code Camp: What is Python?

What is Python?

Speaker: Wesley Chun (wescpy@gmail.com)

Intro (from Wikipedia)

Python is a general-purpose, high-level programming language. Its design philosophy emphasizes programmer productivity and code readability. It supports multiple programming paradigms (primarily object oriented, imperative, and functional) and features a fully dynamic type system and automatic memory management. it is often used as a scripting language.

Background

• Invented by a Dutchman (Guido van Rossum) in 89 (released 91)
• Inherits from C/C++, LISP, Perl, Java amongst others…
• Named after Monty Python
• Used a lot for QA and Testing

Topics Wes will cover:

• Python Object Types
• Loops and conditionals
• Files, Functions and Modules
• OOP
• Philosophy, Concepts, Syntax

Why Python?
Advantages:

• Simle syntax
• Rapid development
• Mutli platform OS
• OO
• Exception Handling
• Functional programming (incl Lambda)
• Multi threaded
• Memory managemwnt (just like Java)
• Extensible

Disadvantages

• Slower than standard compiled languages (like C, C++). Also slower than Java.
• Obscure syntax (indentation rather than braces)
• Some idiosyncrasies
• Little marketting (mostly word of mouth)

Objects

• Allocated on assignment (Dynamic typing) – i.e. x=5 {compiler figures out x is of type number}
• Uses refs (aka aliases), similar to pointers
• Call by reference or value? Both. Neither. Depends on the object!
• Memory management – done by reference counting.

Variables and Expressions

• a = 123 //Note no declarations needed
• a = ‘Python’ (123 can now be garbage collected);

Constructs

• Lists are Python’s arrays. But there are heterogeneous.
• Dictionaries – Python’s only mapping type
  Mutable, resizable hash tables
  Mappings of keys to values
  Key collisions are not allowed
  Values are arbitrary Python objects
  e.g. d.keys() //list pf keys

Finally

• Python 3 will not be backwards compatible (currently on v2.6)

Links

• Why Python?