Mode finding's in Python lists

find_mode.py

def mode(xs):
    """
    This returns the mode of the values in xs. xs is a standard
    Python list with discrete values, which can be of any hashable
    value.

    Fo this problem, think about using a dictionary in some way.
    What could be the keys? The values? Also remember that dictionaries
    are UNORDERED--in other words, there is no guaranteed order.

    Parameters
    ----------
    xs: Values for which to find the mode.

    Returns
    -------
    There are a few possibilities:

    1. Empty list: Return None
    2. One element in list: Return that element
    3. There are ties in the counts of the items: Return ANY tied item.
    4. There is an item with a clear maximum count: Return that iem.
    """
    if len(xs) == 0:
        return None
    elif len(xs) == 1:
        return xs[0]
    else:
        counts = {}
        for x in xs:
            if x in counts:
                counts[x] += 1
            else:
                counts[x] = 1
        maxCount = 0
        maxKey = None
        for key, count in counts.items():
            if count >= maxCount:
                maxCount = count
                maxKey = key
        return maxKey


if __name__ == '__main__':
    print(mode([]))
    print(mode(['alpha']))
    print(mode(['bravo', 'alpha']))
    print(mode(['bravo', 'bravo', 'alpha', 'charlie', 'charlie', 'charlie']))