Write a function file_count(dir) that
takes a string containing a path to a directory, and returns the
total number of files in the directory and its subdirectories
(recursively).
Write a function search(dir, filename)
that takes a string containing a path to a directory, plus a
filename. The function should return True if there is any file with
the given name in the directory or any of its subdirectories
(recursively), otherwise False.
Write a function angle(v, w) that takes two vectors (represented as lists of coordinates) and returns the angle between them in radians. You may not use any loops in your code (and so you will need to use list comprehensions, recursion or higher-order functions).
You will probably want to use the following formula, which relates the dot product of two vectors to the angle θ between them:
v · w = |v| |w| cos θ
Write a function that prints out all values in a binary search tree in order, separated by spaces.
Write a function that takes a binary tree and constructs a second tree that contains all the values from the first tree and is as balanced as possible.
Write a function flatten that takes a
list of lists and returns a list containing all the values from all
sublists:
>>> flatten([[5, 2], [6], [8, 3]]) [5, 2, 6, 8, 3]
Write a function deepFlatten that
takes a list that may contain sublists nested to any level. The
function should return a list containing all the values from all the
sublists:
>>> deepFlatten([ [[5, 2], 6], [8, 3], [[[[10]]]] ]) [5, 2, 6, 8, 3, 10]
Write a program that lets the user draw squares by dragging the mouse. Each square should have a random color.
Extend the previous program so that the user can move a square to a new position by clicking and dragging it. A moved square should rise to the top of the Z-order.
Write a program that displays balloons with random colors. Every 3 seconds, a new balloon should appear near the bottom of the screen. Each balloon should rise until it reaches the top of the screen, then vanish.
Extend your program from the previous exercise, turning it into a simple video game. Each time the player clicks a balloon, it should pop and the user should gain a point. If any balloon reaches the top of the screen, the player has lost and the game is over. As the game proceeds, balloons should appear more frequently and move more quickly, so that the game becomes harder and harder. Display a score at the top of the screen.