7. Exercises¶

1. Fill out the main function below so that you handle two exceptions that may be raised by your call to some_function. If this function raises a ValueError, print “value error happening now”; if this function raises a UnicodeError, print “unicode error happening now”. Make sure your code can handle both errors. (Note: since some_function isn’t filled out, neither exception will be raised when you run the program.)

   def some_function(): # Imagine code that could raise value or unicode errors pass def main(): # Put your exception handling code below some_function() if __name__ == "__main__": main()

   def some_function(): # Imagine code that could raise value or unicode errors pass def main(): try: some_function() except UnicodeError: print("unicode error happening now") except ValueError: print("value error happening now") if __name__ == "__main__": main()

These next several problems are variations on a theme. Each will have you return a string that consists of a shape built out of # (hash) characters. It is left up to you to add the code you would need to run your functions (i.e., adding a main function and calling the respective function). These problems build in difficulty, and are examples in how solving smaller problems can lead you to incrementally build the solutions to larger problems.

2. Write a function line(n) that returns a line with exactly n hashes.

   Example:

   print(line(5))

   Output:

   #####

   def line(n): line_str = '' for i in range(n): line_str = line_str + '#' return line_str def main(): print(line(5)) if __name__ == "__main__": main()

3. Write a function square(n) that returns an n by n square of hashes. Utilize your line function.

   Example:

   print(square(5))

   Output:

   #####
   #####
   #####
   #####
   #####
   

   def line(n): line_str = '' for i in range(n): line_str = line_str + '#' return line_str def square(n): square_str = '' for i in range(n): square_str += (line(n) + '\n') return square_str def main(): print(square(5)) if __name__ == "__main__": main()

4. Write a function rectangle(width, height) that returns a rectangle of the width and height given by the parameters. Again, utilize your line function to do this.

   Example:

   print(rectangle(5, 3))

   Output:

   #####
   #####
   #####
   

   def line(n): line_str = '' for i in range(n): line_str = line_str + '#' return line_str def rectangle(width, height): rectangle_str = '' for i in range(height): rectangle_str += (line(width) + '\n') return rectangle_str def main(): print(rectangle(5, 3)) if __name__ == "__main__": main()

5. Write a function stairs(n) that prints the pattern shown below, with height n. Again, utilize your line function to do this.

   Example:

   stairs(5))

   Output:

   #
   ##
   ###
   ####
   #####
   

   def line(n): line_str = '' for i in range(n): line_str = line_str + '#' return line_str def stairs(n): stair_str = '' for level_len in range(n): stair_str += (line(level_len+1) + '\n') return stair_str def main(): print(stairs(5)) if __name__ == "__main__": main()

6. Write a function space_line(spaces, hashes) that returns a line with exactly the specified number of spaces, followed by the specified number of hashes.

   Example:

   print(space_line(3,5))

   Output:

   #This is where the edge is, so there's 3 spaces before hashes
      #####
   

   def space_line(spaces, hashes): return spaces * ' ' + hashes * '#' def main(): print(space_line(3, 5)) if __name__ == "__main__": main()

7. Write a function triangle(n) that returns an upright triangle of height n.

   Example:

   print(triangle(5))

   Output:

       #
      ###
     #####
    #######
   #########
   

   def space_line(spaces, hashes): return spaces * ' ' + hashes * '#' def triangle(n): triangle_str = '' for i in range(n): triangle_str += (space_line(n-i-1, 2*i+1) + '\n') return triangle_str def main(): print(triangle(5)) if __name__ == "__main__": main()

8. Write a function diamond(n) that returns a diamond where the triangle formed by the top portion has height n. Notice that this means the diamond has 2n - 1 rows.

   Example:

   diamond(5))

   Output:

       #
      ###
     #####
    #######
   #########
    #######
     #####
      ###
       #
   

   def space_line(spaces, hashes): return spaces * ' ' + hashes * '#' def triangle(n): triangle_str = '' for i in range(n): triangle_str += (space_line(n-i-1, 2*i+1) + '\n') return triangle_str def diamond(n): diamond_str = triangle(n) for i in range(n-2, -1, -1): diamond_str += (space_line(n-i-1, 2*i+1) + '\n') return diamond_str def main(): print(diamond(5)) if __name__ == "__main__": main()