Python A readable, dynamic, pleasant, flexible, fast and powerful language

1. Introduction to Python
A readable, dynamic, pleasant,
flexible, fast and powerful language
Nowell Strite
Manager of Tech Solutions @ PBS
nowell@strite.org

2. Overview
• Background
• Syntax
• Types / Operators / Control Flow
• Functions
• Classes
• Tools

3. What is Python
• Multi-purpose (Web, GUI, Scripting, etc.)
• Object Oriented
• Interpreted
• Strongly typed and Dynamically typed
• Focus on readability and productivity

4. Features
• Batteries Included
• Everything is an Object
• Interactive Shell
• Strong Introspection
• Cross Platform
• CPython, Jython, IronPython, PyPy

5. Who Uses Python
• Google
• PBS
• NASA
• Library of Congress
• the ONION
• ...the list goes on...

6. Releases
• Created in 1989 by Guido Van Rossum
• Python 1.0 released in 1994
• Python 2.0 released in 2000
• Python 3.0 released in 2008
• Python 2.7 is the recommended version
• 3.0 adoption will take a few years

7. Syntax

8. Hello World
hello_world.py

9. Indentation
• Most languages don’t care about
indentation
• Most humans do
• We tend to group similar things together

10. Indentation
The else here actually belongs to the 2nd if statement

11. Indentation
The else here actually belongs to the 2nd if statement

12. Indentation
I knew a coder like this

13. Indentation
You should always be explicit

14. Indentation
Text
Python embraces indentation

15. Comments

16. Types

17. Strings

18. Numbers

19. Null

20. Lists

21. Lists

22. Dictionaries

23. Dictionary Methods

24. Booleans

25. Operators

26. Arithmetic

27. String Manipulation

28. Logical Comparison

29. Identity Comparison

30. Arithmetic Comparison

31. Control Flow

32. Conditionals

33. For Loop

34. Expanded For Loop

35. While Loop

36. List Comprehensions
• Useful for replacing simple for-loops.

37. Functions

38. Basic Function

39. Function Arguments

40. Arbitrary Arguments

41. Fibonacci

42. Fibonacci Generator

43. Classes

44. Class Declaration

45. Class Attributes
• Attributes assigned at class declaration
should always be immutable

46. Class Methods

47. Class Instantiation &
Attribute Access

48. Class Inheritance

49. Python’s Way
• No interfaces
• No real private attributes/functions
• Private attributes start (but do not end)
with double underscores.
• Special class methods start and end with
double underscores.
• __init__, __doc__, __cmp__, __str__

50. Imports
• Allows code isolation and re-use
• Adds references to
variables/classes/functions/etc. into current
namespace

51. Imports

52. More Imports

53. Error Handling

54. Documentation

55. Docstrings

56. Tools

57. Web Frameworks
• Django
• Flask
• Pylons
• TurboGears
• Zope
• Grok

58. IDEs
• Emacs
• Vim
• Komodo
• PyCharm
• Eclipse (PyDev)

59. Package Management

60. Resources
• http://python.org/
• http://diveintopython.org/
• http://djangoproject.com/

61. Example

62. Going Further
• Decorators
• Context Managers
• Lambda functions
• Generators
• ...

63. Questions?

64. Thanks!