The file a1.py is a starting template. Edit this file to develop your solutions. The two files test_classes.py and test_functions.py contain a few simple tests that will help you in debugging your solutions. To run the tests, in bash:

python3 -m unittest test_classes.py

python3 -m unittest test_functions.py

def is_multiple_of_4(n):
    """Return True if n is a multiple of 4; False otherwise."""
    pass

def last_prime(m):
    """Return the largest prime number p that is less than or equal to m.
    You might wish to define a helper function for this.
    You may assume m is a positive integer."""
    pass

def quadratic_roots(a, b, c):
    """Return the roots of a quadratic equation (real cases only).
    Return results in tuple-of-floats form, e.g., (-7.0, 3.0)
    Return "complex" if real roots do not exist."""
    pass

def new_quadratic_function(a, b, c):
    """Create and return a new, anonymous function (for example
    using a lambda expression) that takes one argument x and 
    returns the value of ax^2 + bx + c."""
    pass

def perfect_shuffle(even_list):
    """Assume even_list is a list of an even number of elements.
    Return a new list that is the perfect-shuffle of the input.
    For example, [0, 1, 2, 3, 4, 5, 6, 7] => [0, 4, 1, 5, 2, 6, 3, 7]"""
    pass

def list_of_3_times_elts_plus_1(input_list):
    """Assume a list of numbers is input. Using a list comprehension,
    return a new list in which each input element has been multiplied
    by 3 and then has 1 added to it."""
    pass

def quadruple_vowels(text):
    """Return a new version of text, with all the vowels quadrupled.
    For example:  "The *BIG BAD* wolf!" => "Theeee *BIIIIG BAAAAD* woooolf!".
    For this exercise assume the vowels are 
    the characters A,E,I,O, and U (and a,e,i,o, and u).
    Maintain the case of the characters."""
    pass

def count_words(text):
    """Return a dictionary having the words in the text as keys,
    and the numbers of occurrences of the words as values.
    Assume a word is a substring of letters and digits and the characters
    '-', '+', *', '/', '@', '#', '%', and "'" separated by whitespace,
    newlines, and/or punctuation (characters like . , ; ! ? & ( ) [ ] { } | : ).
    Convert all the letters to lower-case before the counting."""
    pass

class Polygon:

  def __init__(self, n_sides, lengths=None, angles=None):
    # Additional code will go here.

  def is_rectangle(self):
    """ returns True if the polygon is a rectangle,
    False if it is definitely not a rectangle, and None
    if the angle list is unknown (None)."""
    pass

  def is_rhombus(self):
    pass

  def is_square(self):
    pass

  def is_regular_hexagon(self):
    pass

  def is_isosceles_triangle(self):
    pass

  def is_equilateral_triangle(self):
    pass

  def is_scalene_triangle(self):
    pass

my_tri = Polygon(3, [3,4,5])
my_tri.is_rectangle() # False
my_tri.is_isosceles_triangle() # False
my_tri.is_scalene_triangle() # True

your_tri = Polygon(3, angles=[60, 60, 60])
your_tri.is_equilateral_triangle() # True
your_tri.is_isosceles_triangle() # True
your_tri.is_scalene_triangle() # False

my_rect = Polygon(4, angles=[90, 90, 90, 90])
my_rect.is_rectangle() # True
my_rect.is_square() # None (unknown)

your_diamond = Polygon(4, [1, 1, 1, 1], [114, 66, 114, 66])
your_diamond.is_rectangle() # False
your_diamond.is_rhombus() # True
your_diamond.is_square() # False

1. Q. Will we be graded on style?
   A. The staff reserves the right to deduct points for sloppy formatting or lack of comments or comments that are inconsistent, misleading, irrelevant or very unclear in their context.
2. Q. In the polygon classes example, can we assume that we will be dealing with valid polygons?
   A. Yes.
3. Q. When I submit my code, will additional test cases be run on my functions, other than those distributed with the starter code?
   A. In general, yes. Also, you are encouraged to develop test cases of your own, to help you debug your code's behavior on possible edge cases.
4. Q. How should my code in the Polygon class know when to return True, False or None, for example with is_square?
   A. When it is possible to determine with certainty that the requirements (e.g., for a square) are satisfied, then return True. If some constraint is violated (e.g., when testing for a square, two sides have different lengths, or there exists an angle that is definitely not 90 degrees) then return False. Otherwise, return None.