How to find longitude and latitude for a list of Regions or Country using Python

Geopy is a Python 2 and 3 client for several popular geocoding web services. Geocoding is the process to identify geographic coordinates like latitude and longitude of a given city/country/address. This is very useful during marking position on the map in data visualization. We use geopy.exec, geocodertimedout, geolocators, geopy.geocoder in the below code to fetch the results

Installation

This module does not come built-in with Python. To install it type the below command in the terminal.

pip install geopy 

Example: Let’s create a pandas dataframe containing a list of regions or countries.

# Import pandas package
import pandas as pd
import numpy as np

# Define a dictionary containing  data
data = {'City':['Bangalore', 'Mumbai', 'Chennai', 'Delhi']}

# Convert the dictionary into DataFrame
df = pd.DataFrame(data)

# Observe the result
df

Output:

Now Let’s find the latitude and longitude of the following regions or countries.

from geopy.exc import GeocoderTimedOut
from geopy.geocoders import Nominatim

# declare an empty list to store
# latitude and longitude of values
# of city column
longitude = []
latitude = []

# function to find the coordinate
# of a given city
def findGeocode(city):

    # try and catch is used to overcome
    # the exception thrown by geolocator
    # using geocodertimedout
    try:

        # Specify the user_agent as your
        # app name it should not be none
        geolocator = Nominatim(user_agent="your_app_name")

        return geolocator.geocode(city)

    except GeocoderTimedOut:

        return findGeocode(city)

# each value from city column
# will be fetched and sent to
# function find_geocode
for i in (df["City"]):

    if findGeocode(i) != None:

        loc = findGeocode(i)

        # coordinates returned from
        # function is stored into
        # two separate list
        latitude.append(loc.latitude)
        longitude.append(loc.longitude)

    # if coordinate for a city not
    # found, insert "NaN" indicating
    # missing value
    else:
        latitude.append(np.nan)
        longitude.append(np.nan)

Showing the output produced as dataframe.

# now add this column to dataframe
df["Longitude"] = longitude
df["Latitude"] = latitude

df

Output: