Learning Python

L E A R N I N G T O P R O G RA M

PYTHON

WHY LEARN TO PROGRAM?

• An important skill in making things for online

media: problem solving

• Process of learning to program: Practice and

improve your problem-solving skills

• Thinking in a structured way

• Learning how to find answers by a combination

of online searching and trial-and-error

WHY PYTHON?

Python is one

of the most-

used

programming

languages

today.Source:

https://github.com/mjwillson/ProgLangVisualise

WHY NOT JAVASCRIPT?

• JavaScript is a must for Web development today.

• If you already knew how to program, you could jump

straight into JavaScript and not learn Python.

• As a first programming language, Python is easier to

learn than JavaScript.

• The techniques you learn as you learn Python will

help you understand JavaScript more quickly.

http://www.quora.com/Is-it-better-to-learn-Python-or-J

avaScript-as-a-first-

language

USING PYTHON

• There are two ways to use Python:

• Interactive mode

• Script mode

• In interactive mode, you type Python programs

and the Python interpreter displays the result

immediately …

Source: Think Python, by Allen B. Downey (O’Reilly Media: 2012), pages 2–3

I N T E RAC T I V E M O D E

PYTHON

USING PYTHON

• There are two ways to use Python:

• Interactive mode

• Script mode

• In script mode, you write code in a text file, save

it, and then use the interpreter to execute (or run)

the contents of the file (which is called a script)

• Python scripts have filenames that end with .py

Source: Think Python, by Allen B. Downey (O’Reilly Media: 2012), pages 2–3

T H I S I S A S C R I P T , S H O W N I N A T E XT E D I T O R

PYTHON

When you run a Python script (left) in the Python interpreter, the output (but not the stored script) is displayed onscreen (right).

WHAT A PROGRAM DOES

• Input: Get data from the keyboard, a file, or some other device

• Output: Display data on the screen, or send data to a file or

other device

• Math: Perform basic mathematical operations like addition and

multiplication

• Conditional execution: Check for certain conditions and

execute the appropriate code

• Repetition: Perform some action repeatedly, usually with some

variation

Source: Think Python, by Allen B. Downey (O’Reilly Media: 2012), page 3

WHAT A PROGRAM DOES (2)

• Input: (1) run a script; (2) raw_input

• Output: (1) print; (2) create and write to text

files

• Math: +, –, /, *, %, >, <, >=, <=, ==

• Conditional execution: if, elif, else

• Repetition: for, whileYou will learn how to do each of these, which is pretty much all there is to programming. (I’m lying a little bit.)

“Every program you’ve ever used, no

matter how complicated, is made up of

instructions that look pretty much like

these. So you can think of programming

as the process of breaking a large,

complex task into smaller and smaller

subtasks until the subtasks are simple

enough to be performed with one of

these basic instructions.”

Source: Think Python, by Allen B. Downey (O’Reilly Media: 2012), page 4

DEBUGGING

Errors are bugs. Finding and fixing them is

debugging.

• Syntax errors: Structure and rules, such as:

“Parentheses come in pairs”

• Runtime errors: Appear while the program is

running (these are called exceptions)

• Semantic errors: Your script runs but does not do

what you wanted it to doSource: Think Python, by Allen B. Downey (O’Reilly Media: 2012), pages 4–5

In the practice of programming—of

writing programs—a lot of the work is in

the debugging.

Each error becomes a puzzle to be

solved.

“Why doesn’t it work the way I want it to

work?”

The process of learning to program is a

process of problem-solving.

• Think Python, by Allen B. Downey

http://www.greenteapress.com/thinkpython/

• Learn Python the Hard Way, by Zed A. Shaw

http://learnpythonthehardway.org/

• Codecademy: Python

http://www.codecademy.com/tracks/python

RESOURCES

L E A R N I N G T O P R O G RA M

PYTHON

Presentation by Mindy McAdams, University of Florida[ 2012 ]