Using regex to convert latitude and longitude coordinates of degrees/minutes/direction to decimal in python

Question

I am trying to convert latitude and longitude data into python which are in the following format:

Latitude    Longitude   
27º59' N    86º55'E 

This data was extracted from the following web page and converted into a csv file: http://www.peaklist.org/WWlists/WorldTop50.html

I made the code to convert but got the result as Nan. I tried several different ways and the last code I tried was the following:

data['Longitude'] = data['Longitude'].str.extract('°\'([N|S|E|W])', expand=True)
(parts[0].astype(int) + parts[1].astype(float) / 60) * parts[2].map({'N':1, 'S':-1, 'E': 1, 'W':-1})

The data in the latitude and longitude columns are in string format. Thank you

Answer 1

Using this as a basis: https://www.pgc.umn.edu/apps/convert

And having:

   Latitude Longitude
0  27º59' N   86º55'E

I think you can start by creating a function for DDM to DD conversion, note that since you don’t have seconds then 0 is assumed in that place:

import re

def convert(s):
    degrees, minutes, direction = re.split('[º\' "]+', s)
    dd = float(degrees) + float(minutes)/60
    return dd*-1 if direction in 'SW' else dd
... 
data['Latitude_dd'] = data['Latitude'].apply(convert)
data['Longitude_dd'] = data['Longitude'].apply(convert)

We get:

   Latitude Longitude  Latitude_dd  Longitude_dd
0  27º59' N   86º55'E    27.983333     86.916667

I think it fits because your example being Mount Everest (http://www.peaklist.org/WWlists/WorldTop50.html) the result gave precisely there: