def move_column(column, max=3, length=4):
    """
    Moves the elements of the column from left to right as in 2048.

    Modifies the given array.

    Parameters
    ----------
    column : numpy array
        A numpy array of length 4 (not necessarily).
    max : int, optional
        The first position to check, between 0 and 3 included (default is 3).

        For example, 3 to check every value,
        2 to ommit the last one in the vector, ...
    length : int, optional
        The length of the column (default is 4).

    Returns
    -------
    boolean
        A boolean indicating if changes occurred.
    """
    modif = False
    i = max - 1

    while 0 <= i < max:
        if column[i] != 0:
            j = i
            while i < length - 1 and column[i + 1] == 0:
                i += 1
            if j != i:
                column[i] = column[j]
                column[j] = 0
                modif = True
        i -= 1

    return modif