Convert DD (decimal degrees) to DMS (degrees minutes seconds) in Python?

Question

How do you convert Decimal Degrees to Degrees Minutes Seconds In Python? Is there a Formula already written?

Answer 1

If you want to handle negatives properly, the first non-zero measure is set negative. It is counter to common practice to specify all of degrees, minutes and seconds as negative (Wikipedia shows 40° 26.7717, -79° 56.93172 as a valid example of degrees-minutes notation, in which degrees are negative and minutes have no sign), and setting degrees as negative does not have any effect if the degrees portion is 0. Here is a function that adequately handles this, based on Paul McGuire's and baens' functions:

def decdeg2dms(dd):
    negative = dd < 0
    dd = abs(dd)
    minutes,seconds = divmod(dd*3600,60)
    degrees,minutes = divmod(minutes,60)
    if negative:
        if degrees > 0:
            degrees = -degrees
        elif minutes > 0:
            minutes = -minutes
        else:
            seconds = -seconds
    return (degrees,minutes,seconds)

Answer 2

Now we can use LatLon library...

https://pypi.org/project/LatLon/

>> palmyra = LatLon(Latitude(5.8833), Longitude(-162.0833)) # Location of Palmyra Atoll in decimal degrees
>> palmyra = LatLon(5.8833, -162.0833) # Same thing but simpler! 
>> palmyra = LatLon(Latitude(degree = 5, minute = 52, second = 59.88),
                     Longitude(degree = -162, minute = -4.998) # or more complicated!
>> print palmyra.to_string('d% %m% %S% %H') # Print coordinates to degree minute second
('5 52 59.88 N', '162 4 59.88 W')`

Answer 3

This is exactly what divmod was invented for:

>>> def decdeg2dms(dd):
...   mnt,sec = divmod(dd*3600,60)
...   deg,mnt = divmod(mnt,60)
...   return deg,mnt,sec

>>> dd = 45 + 30.0/60 + 1.0/3600
>>> print dd
45.5002777778
>>> decdeg2dms(dd)
(45.0, 30.0, 1.0)

Answer 4

The sign has better be returned separately, so that it can be used to choose from ('N', 'S') or ('E', 'W'), for example.

import math

def dd_to_dms(degs):
    neg = degs < 0
    degs = (-1) ** neg * degs
    degs, d_int = math.modf(degs)
    mins, m_int = math.modf(60 * degs)
    secs        =           60 * mins
    return neg, d_int, m_int, secs

Answer 5

Improving @chqrlie answer:

    def deg_to_dms(deg, type='lat'):
        decimals, number = math.modf(deg)
        d = int(number)
        m = int(decimals * 60)
        s = (deg - d - m / 60) * 3600.00
        compass = {
            'lat': ('N','S'),
            'lon': ('E','W')
        }
        compass_str = compass[type][0 if d >= 0 else 1]
        return '{}º{}\'{:.2f}"{}'.format(abs(d), abs(m), abs(s), compass_str)

Answer 6

Use fmod and rounding to get the degrees and fraction separated. Multiply the fraction by 60 and repeat to get minutes and a remainder. Then multiply that last part by 60 again to get the number of seconds.