x = 1
y = 2
z = 3

def mystery1(a, z):
    """
    What this function does is a mystery. Short of.
    :param a: (num)
    :param z: (num)
    :return: None
    """
    s = 1000
    print("Mystery1 s: " + str(s))
    print("Mystery1 x: " + str(x))
    print("Mystery1 y: " + str(y))
    print("Mystery1 z: " + str(z))
    z = 100


# def mystery2():
#     """
#     This function will produce an error as it tries to access a variable out of scope.
#     :return: None
#     """
#     print("Mystery2 a: " + str(a))

def mystery3(any_list):
    """
    What this function does is a mystery. Short of.
    :param any_list: (list) list of at least one element
    :return: None
    """
    any_list[0] = "banana"
    print("mystery3 any_list contains:" + str(any_list))


def mystery4(any_list):
    """
    What this function does is a mystery. Short of.
    :param any_list: (list) list of at least one element
    :return: None
    """
    print("mystery4 any_list contains:" + str(any_list))
    any_list = ["pineapple"]
    print("mystery4 any_list now contains:" + str(any_list))



mystery1(10, 20)

print("x is now: " + str(x))
print("y is now: " + str(y))
print("z is now: " + str(z))

# uncomment to produce error.
# mystery2()

some_list = ["apple"]
mystery3(some_list)
print("some_list contains:" + str(some_list))

mystery4(some_list)
print("some_list now contains:" + str(some_list))