def getNums(numStr):
    """
    Extract number or range of numbers from data file

    Examples
    --------
    >>> getNums('4')
    [4]
    >>> getNums('4-7')
    [4,5,6,7]


    """
    if "-" in numStr:
        # range of numbers
        nums = [int(n) for n in numStr.split("-")]
        nums = range(nums[0], nums[1] + 1)
    else:
        nums = [int(numStr)]  # just one number. Keep in list to be general.

    return nums