Introduction to Python: A Dynamic Language for Readable and Powerful Programming

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