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Lab 23: Lists

As usual, create a directory to hold today's files. All programs that you write today should be stored in this directory. 

    $ cd ~/cs120/labs
    $ mkdir lab23 
    $ cd lab23

Practice 1

Practice Problem 1

Write a function double_all(a_list), which takes a list of floating point numbers. Your function should return a version of a_list with all values doubled. 










Practice 2












  
Practice Problem 2


  

      Write a function remove_all(a_list, an_element),
      which
        takes a list and some element.  Your function should remove
      all
      occurances of an_element from a_list, and return the
      resulting list.
  

  


  

  

        
  

  









Flappy Bird



  Flappy Bird was an incredibly popular game back in the Spring of
  2013.  It made A LOT of money, especially considering it was a
  "free" game.  The game was suddenly removed from the App Store, but
  the initial success of the game resulted in many clones being
  available almost instantly.  The overall game is not super difficult
  to replicate, now that we have lists!




Details




  Create a python program in a file called flappy.py.  This
  file will replicate a somewhat simplified version of the Flappy
  Bird game.  Towards this end, you will want to replicate the
  gravity function demonstrated in class earlier today.  Don't forget
  to place
  the graphics
  module
  and sprite
  module in your directory.





  Every 3 seconds, a new pipe should be generated.  It should start at
  the right side of the screen, and slowly work its way to the left
  side of the screen.  The height of the pipe should be randomly
  generated. Every pipe generated should be stored in a
  list, so that all of the pipes can be updated at once.





  Create a function called move_pipes(pipe_list),
  which takes a list of Sprite objects which represent pipes in the
  game.  This function should move all of the pipes to the left by the
  same amount.  If a pipe is past the left edge of the screen, you
  should remove.





  Also create a function called check_collision(bird_sprite,
  pipe_list), which takes the bird sprite object and a list of
  the pipe objects.  It should return True if the bird sprite
  is colliding with any of the pipes.





  Use these two functions to replicate a simple version of flappy
  bird, with pipes only on one side (bottom) of the screen.





  

    
  

  

    
  





Example





Hint




  
  

    
    
      
  • 
	Every sprite object has 2 important attributes:  x
	and y.  These are the x and y coordinates the sprite
	is being drawn at.  You can update these directly, and those
	values will be used the next time you call graphics.draw_sprite.
      
    • 
      
  • 
	The sprite is drawn centered at the specified x and y
	coordinates.  When you generate the new y coordinate for the
	sprite, you should compute the y coordinate for the top of the
	pipe.  Then add half the height of the pipe of the pipe to get
	the center y coordinate of the pipe.
      
    • 
      
  • 
	It might seem natural to delete items from the list as you are
	looping over its elements.  However, modifying that list will
	likely result in unforseen runtime errors.  Because of the
	structure of the list, only the first element has a chance of
	being off the screen.  Instead of checking each element, you
	only need to check the sprite at index 0.
      
    • 
    

  






  
Challenge

  

    Modify your program so that there are pipe sprites along the top
    of the screen as well.  You will either need to flip the pipe
    sprite, or find a different sprite for the top.