Converting fractional days to H:M:S.MS - Two examples

Of the two methods of calculating a fractional day to local time, which one would you consider the best way and why?

Edit: 'Fractional day' means here the decimal part of a Julian day jd: jd - (math.floor(jd - 0.5) + 0.5) (this is because 0:00:00 is at jd.5)

@classmethod
def fromfractional(cls, frac, **kwargs):
    changed = False
    f = lambda x: decimal.dec(floor(x))
    if not isinstance(frac, decimal.Decimal):
        frac = decimal.dec(frac)
    hours = decimal.dec(D24 * (frac - f(frac)))
    if hours < 1:
        hours += 1 # Or else microseconds won't be calculated correctly
        changed = True
    minutes = decimal.dec(D60 * (hours - f(hours)))
    seconds = decimal.dec(D60 * (minutes - f(minutes)))
    ms = decimal.dec(DKS * (seconds - f(seconds)))
    if changed:
        hours -= 1

    return int(hours), int(minutes), int(seconds), int(ms)

@classmethod
def fromfractional2(cls, x):
    d = lambda x: decimal.Decimal(str(x))
    total = d(x) * d(86400000000000)
    hours = (total - (total % d(3600000000000))) / d(3600000000000)
    total = total % d(3600000000000)
    minutes = (total - (total % d(60000000000))) / d(60000000000)
    total = total % d(60000000000)
    seconds = (total - (total % d(1000000000))) / d(1000000000)
    total = total % d(1000000000)
    ms = (total - (total % d(1000000))) / d(1000000)
    total = total % d(1000000)
    mics = (total - (total % d(1000))) / d(1000)

    return int(hours), int(minutes), int(seconds), int(ms)


D24 = decimal.Decimal('24')
DMS = decimal.Decimal('86400000.0')
D60 = decimal.Decimal('60') 
D3600 = decimal.Decimal('3600')
D1440=decimal.Decimal('1400')
DKS=decima开发者_开发技巧l.Decimal('1000')
DTS=decimal.Decimal('86400')

I think you are trying to get from something like:

1.2256 days

To:

1 day, 5 hours, 24 minutes, 51 seconds

but with microseconds, too?

Here's how I generated the above response:

def nice_repr(timedelta, display="long"):
    """
    Turns a datetime.timedelta object into a nice string repr.

    display can be "minimal", "short" or "long" [default].

    >>> from datetime import timedelta as td
    >>> nice_repr(td(days=1, hours=2, minutes=3, seconds=4))
    '1 day, 2 hours, 3 minutes, 4 seconds'
    >>> nice_repr(td(days=1, seconds=1), "minimal")
    '1d, 1s'
    """

    assert isinstance(timedelta, datetime.timedelta), "First argument must be a timedelta."

    result = ""

    weeks = timedelta.days / 7
    days = timedelta.days % 7
    hours = timedelta.seconds / 3600
    minutes = (timedelta.seconds % 3600) / 60
    seconds = timedelta.seconds % 60

    if display == 'minimal':
        words = ["w", "d", "h", "m", "s"]
    elif display == 'short':
        words = [" wks", " days", " hrs", " min", " sec"]
    else:
        words = [" weeks", " days", " hours", " minutes", " seconds"]

    values = [weeks, days, hours, minutes, seconds]

    for i in range(len(values)):
        if values[i]:
            if values[i] == 1 and len(words[i]) > 1:
                result += "%i%s, " % (values[i], words[i].rstrip('s'))
            else:
                result += "%i%s, " % (values[i], words[i])

    return result[:-2]