Notes from Python lab 1, Tuesday 2007.09.25

1. Python can be run interactively by typing "python" at the $ shell prompt.
You will see the >>> prompt. You can interactively do Python statements, or
you can import a Python script that has definitions followed by commands. The
chaos.py example on page 12 of the textbook shows how to import a script. Note
that the main() function is both defined and then later called in the script.
For this example, the main() function will be called (and your program
executed) when the script is imported. Be sure your script has two blank
lines after the doubly indented defintion of the main() function before the
next statement calling main() on the last line of the file.

2. The preferred way to develop Python programs is to edit them in a file with
your favorite editor and run them in another command line window. Regarding
the editor, the scite editor on the lab systems has Python formatting built in,
as does vi and emacs. For executing your programs, you can import your
scripts as shown on p12 and p13 of the textbook, or you can enter
"python myscript.py" at the shell command prompt.  The problem I've had with
the import method is that any changes I make to the file seem to require me
to re-start the Python interpreter in order to import the new changes to the
file. This doesn't seem right to me, so I prefer the command line method for
executing Python programs.

3. We used the following simple set of Unix commands in the lab:
  passwd		  change password in Linux
  pwd			  print working directory
  ls 			  list the files in the working directory
  mkdir	<myname>  make a new directory <myname>
  cd <myname>     change directories to the <myname> directory
  cd              change back to your home directory
  more <myfile>   scrool through <myfile> in the terminal window.
  rm <myfile>     remove <myfile>
  cp <f1> <f2>    copy file <f1> to file <f2>.
  mv <f1> <f2>    move file <f1> to file <f2> (ie, rename <f1> to <f2>).
  lpr <file>      send <file> to the printer
  nano <file>     edit <file>

You should keep your work organized in your directory. I recommend 
separate python directory and a separate directory under the python 
directory for each chapter of the textbook. When you run the python
interpreter, be sure you start it in the same directory as the files
that contain your Python scripts.

4. Isaac showed us how to create a directory "web" in our home directory
and access any files in that directory from a web browser anywhere in the
world. You can build your own web site there.