In Class: Week 2 (strings, string functions, string operators)

If you have not already copied over the week 2 in-class files, then create a week02 subdirectory in your cs21/class directory, and copy over some python files from my public directory into it:

    % cd 
    % cd cs21/class
    % pwd
      /home/your_user_name/cs21/class

    % mkdir week02        
    % cd week02
    % pwd
      /home/your_user_name/cs21/class/week02

    % cp ~newhall/public/cs21/week02/* .
    % ls
	

1. String operators: open test_string.py in vim. We will try out some of the string functions (len, ord, chr) and some of the string operators (+ (concatenation), * (repetition), : (slice)

2. Pattern of stars problems: open test_stars.py. We are going to write programs to print out the following patterns of stars. Let's start with the first one.

     (1)   when num is 4:             when num is 5:
            * * * *                   * * * * *
            * * * *                   * * * * *
            * * * *                   * * * * *
            * * * *                   * * * * *
                                      * * * * *
     (2)    - - - - * * * *
            - - - - * * * *
            - - - - * * * *
            - - - - * * * *
                            
     (3)    *
            * * 
            * * * 
            * * * *