In Class: Week 1 Monday

If you want to try out a python program do the following (we will do something like this in class on Wednesday, so if you do not get through this, that is okay):

1. create a subdirectory class in your cs21 directory:

         % cd 
         % cd cs21
         % mkdir class
         % cd class
         % pwd
   	

2. create a week01 subdirectory of your class directory

         % mkdir week01        # do this from your cs21/class subdirectory
         % cd  week01
         % pwd
   	

3. open a new file named hellothere.py in vim and type in the following python code (indentation is important), save and exit vim (:wq):

     def main():
   	   
         print "hello there!"
   
     main()
   

4. at the Unix prompt run the python interpreter on your program and you should see it print the message "hello there!" to the terminal:

     % python hellothere.py
       hello there!
     %
   

   you can also run this program on the python interpreter in interactive mode:

     # runs hellothere.py in interactive mode:
     % python -i hellothere.py
     >>>
   

   >>> is the python interpreter prompt, at this prompt you can enter other python code that the interpreter will interpret:

     >>> print "hello, who are you?"
   

   To exit the python interpreter hold down the control and the D keys together (CNTL-D)

   you can also just start the python interpreter in interactive mode without giving it a python code file to run:

     % python
     >>>