range.py

"""Given list of numbers, return smallest & largest number as a tuple.

For example::

    >>> find_range([3, 4, 2, 5, 10])
    (2, 10)

    >>> find_range([43, 3, 44, 20, 2, 1, 100])
    (1, 100)

For an empty list, it should return `None` as both smallest and largest::

    >>> find_range([])
    (None, None)

Make sure it works with a list of one item, which is both smallest and
largest::

    >>> find_range([7])
    (7, 7)
"""


def find_range(nums):
    """Given list of numbers, return smallest & largest number as a tuple."""

    # Simple solution leveraging built-in min/max:

    # if not nums:
    #     return (None, None)
    # return (min(nums), max(nums))

    # Alternatively...without using min/max or sort...

    if not nums:
        return (None, None)

    min = nums[0]
    max = nums[0]

    for num in nums:
        if num > max:
            max = num
        elif num < min:
            min = num
        else:
            continue

    return (min, max)



if __name__ == '__main__':
    import doctest

    if doctest.testmod().failed == 0:
        print "\n*** ALL TESTS PASSED. HOORAY!\n"