Tue Sep 4
Standard beginning : any questions about anything so far?
nuts'n'bolots
getting started
First, it's common for people taking this course to have very different experience levels.
If getting up and running is easy for you, great. I encourage you to brush up on your current skills, and try to stretch a bit wherever you feel you need it.
If all this is brand new, that's OK: get help as needed, and plug away at getting all the pieces in place.
Your first substantial task is to get to the point where you can write and run a python program on your computer. (Or, if you don't have a computer, on the lab computers. If so, please do check in with me.)
The basics look like this :
- Set up a folder on your computer for your work for this semester. (If you're not sure how to do this, check in with me or Sam for assistance soon.)
- Choose a texteditor (see above) and create a python program (i.e. hello.py; see below). Don't use a word processor - you'll get extra funky stuff in your source file, and you won't have nice color syntax hints.
- Get to a command prompt (how varies with your computer; see wikipedia: command line interface; called "Terminal" on Mac) and type "python" to see if your computer already has it. If not, install it from one of the choices at http://www.python.org/getit/ .
- Ask for help from Sam, me, or any CS student if you're confused.
(On Windows, getting python up and running and using it may be more convoluted than on a Mac or Unix system, because it isn't already built-in by default. But you should be fine once you learn the drill.)
Here's the "hello world" program in python :
# This file is hello.py - a first short program in python.
print "Hello world"
From a terminal program (the $ is the prompt waiting for you to type), in the same folder as the file (see below for more)
$ python hello.py
Hello world!
You should have this working this week. Again - you need help, ask, don't wait and get behind.
command line vs GUI
A bit more on the command line.
Mac/Unix:
# Mac: The application is /Applications/Utilities/Terminal
# Unix: depends; look for "Terminal" in application menu
$ cd /folder/name # change directory
$ ls # list directory
$ pwd # print working directory
$ python file.py # run python program in file.py
Windows
# XP: Start ... Programs ... Accessories ... Command Prompt
> cd \folder\name # change directory
> dir # list directory
> cd # show current directory
> python file.py # run python program in file.py
running python
And a bit more on running python.
In general, programming can be done with text editors and the command line (which is the "old school" way I'll be showing you) or with an IDE (Integrated Development Environment). Some people swear by IDEs. My opinion is that they hide the details of what's going on, and when you're starting out (like in this class), it's good to understand those details.
The difference between an editor and an IDE is essentially how much can be done from within the application to compile, run, debug etc the program. Or in larger settings, the programming project. If you think you'd rather try an IDE, the list at
http://wiki.python.org/moin/PythonEditors may be helpful.
On a lab mac, run python by launching the "Terminal" program in Applications/Utilities. Then get to right folder, and type "python".
Do make sure you know what folder you're in while you're working with a python file or at the command prompt. If nothing is working, there's a good chance that you're just in the wrong folder.
You can also run python and edit files over the network, by logging in to cs.marlboro.edu - the same machine that's serving up these web pages. The "ssh" (secure shell) program can connect you to your_username@cs.marlboro.edu (after I give you an account; ask if you want one).
Finally, all of this can be done on the lab computers or those in Sci 217.
an example
Demo the chaos program
- type it in, save to a folder, run it.
discuss overview of computers and terminology
- memory / disk / cache
- source code
- compiler
- process
- shell
- operating system
- library
- network
random
chap 2 topics
... if we get that far
- First: have a plan
- comments
- variables
- variable names
- assignment statements : "x = 5" ; "x = x + 1"
- range(n) : a list of things
- "for" loops
- python "gotcha's" (every language has it's quirks) :
- input("prompt") # do use ()
- print "stuff" # don't use ()
- other functions :
