problem_47.py

def coding_problem_47(prices):
    """
    Given a array of numbers representing the stock prices of a company in chronological order, write a function that
    calculates the maximum profit you could have made from buying and selling that stock once. You must buy before you
    can sell it. For example, given [9, 11, 8, 5, 7, 10], you should return 5, since you could buy the stock at 5
    dollars and sell it at 10 dollars.

    >>> coding_problem_47([9, 11, 8, 5, 7, 10])
    5
    """
    pass


if __name__ == '__main__':

    import doctest
    doctest.testmod(verbose=True)