Assignment 2

1. Demo problem. Consider this coding puzzle. Suppose we're asked to print out lines in a pattern like this:

   z
   zy
   zyx
   zyxw
   zyxwv
   zyxwvu
   zyxwvut
   zyxwvuts
   zyxwvutsr
   zyxwvutsrq
     

   And suppose we want to use for-loops to achieve this. How do we go about solving this problem?

   At this point, do not read further and try to address the following:

   • First understand what is being asked.
   • Do see a for-loop or two at work where, as the loops are printing, you'll get the output shown above?
   • Can the problem be broken down into parts, where you can solve the parts and put the solution together afterwards?
   • Try writing some code to get at least some of the output.
   • What are the issues related to strings?

   Now examine the solution

   Don't forget to submit your solutions to the exercises within.

2. Write a program called my_odd_sum.py to compute the sum of all odd numbers in a given range. Here's part of the code:

   m = 10
   n = 20
   
   # Write code to add up the odd numbers between m and n inclusive
   
   # WRITE YOUR CODE HERE
   
   # When m=10, and n=20, you should get 75
     

   Then test out your code by changing m to m=100 and n to n=150. What do you get?

3. Review the example in Module 5 where we made a random sentence. After pulling out random nouns, a verb etc, we built a sentence like so:

       sentence = (
           'The ' + adj + ' ' + noun + ' ' + verb + 's' +
           ' ' + prep + ' a ' + noun2)
     

   In my_avg_sentence_length.py, use a loop to build many such sentences and compute the average sentence length at the end. Print each sentence and at the end, print the average sentence length. (Note: use the sentence construction as above, which will include spaces).

4. In my_geometric_art.py, write code to use drawtool so that the result is:

   

   Here's some code to get started with:

   from drawtool import DrawTool 
   
   dt = DrawTool()
   dt.set_XY_range(0,100, 0,100)
   dt.set_aspect('equal')
   
   # This is how you set the drawing color:
   dt.set_color('b')
   # Other colors: r for red, g for green, m for magenta
   # k for black, w for white, y for yellow, c for cyan
   
   m = 0
   for k in range(0, 41, 10):
       dt.draw_rectangle(k, m, 5, 5)
       m = m + 10
   
   # WRITE YOUR CODE BETWEEN HERE ...
   
   # ... AND HERE.
   dt.display()
     

   Start by downloading drawtool.py into your assignment folder. Then, write the above code in my_geometric_art.py to see that a part of the drawing has been made for you. You can draw a circle with center at (10,20) with radius 5 using the line:

   dt.draw_circle(10, 20, 5)
     

   (Try it).

5. Art project. In my_geometric_art2.py, use the ability to draw rectangles and circles, changing colors where needed, to make a far more impressive work of art. You are also welcome to use other functions in drawtool such as:

   dt.draw_filled_circle(10, 20, 5)
   dt.draw_filled_rectangle(40, 50, 5, 5)
     

   With a limited color and geometric palette, we're confident you can make something Mark Rothko or Piet Mondrian would be proud of.

6. The following program intends to print the integer value of a letter (character) along with the corresponding letter, separately for uppercase first, and then lowercase. The output (edited for length) is something like:

   65-A
   66-B
   67-C
   ...
   90-Z
   97-a
   98-b
   99-c
   ...
   122-z
     

   Here's the program with errors:

   for i in range(65,91):
       print(i+ "-" + chr(i)
   
   for j in range(ord('a'),ord('z')):
       x = char(j)
       print(str(i)+ "-" + x)
     

   Find and fix the errors in fixed_errors1.py.

7. In assignment2.pdf, explore geometric art and the general topic of computer-generated art. What were you able to find? Write a paragraph on a well-known artist and provide a link to the sources you found. Explain what you like in this artist's work and why.

A2.3 Audio:

How to submit:

• Write all your programs and assignment1.pdf in a directory called assignment1.
• Make a zip of the directory and submit that.