Convert coordinates in DMS notation to decimal in Python.

dms2dec.py

#!/env/python
# coding=utf8

"""
Converting Degrees, Minutes, Seconds formatted coordinate strings to decimal. 

Formula:
DEC = (DEG + (MIN * 1/60) + (SEC * 1/60 * 1/60))

Assumes S/W are negative. 
"""

import re

def dms2dec(dms_str):
    """Return decimal representation of DMS
    
    >>> dms2dec(utf8(48°53'10.18"N))
    48.8866111111F
    
    >>> dms2dec(utf8(2°20'35.09"E))
    2.34330555556F
    
    >>> dms2dec(utf8(48°53'10.18"S))
    -48.8866111111F
    
    >>> dms2dec(utf8(2°20'35.09"W))
    -2.34330555556F
    
    """
    
    dms_str = re.sub(r'\s', '', dms_str)
    
    sign = -1 if re.search('[swSW]', dms_str) else 1
    
    numbers = filter(len, re.split('\D+', dms_str, maxsplit=4))

    degree = numbers[0]
    minute = numbers[1] if len(numbers) >= 2 else '0'
    second = numbers[2] if len(numbers) >= 3 else '0'
    frac_seconds = numbers[3] if len(numbers) >= 4 else '0'
    
    second += "." + frac_seconds
    return sign * (int(degree) + float(minute) / 60 + float(second) / 3600)

In Python 3, filter() returns a iterable filter object rather than a list.
numbers should be converted to list using list(): numbers = list(numbers) before subscription.
Otherwise, call method next() to get items one by one from iterable numbers.

Updated to python 3 https://gist.github.com/chrisjsimpson/076a82b51e8540a117e8aa5e793d06ec

@ytzhang0925 there must be a better way" do please share if you wish 👍

very nice. thank you.