Geocoding in QGIS Field Calculator

geocoding.py

# the function needs geopy
# for Windows users, to install geopy, open the OSGEO4W Shell and type: 
# py3_env 
# pip3 install geopy

from qgis.core import *
from qgis.gui import *

from geopy.geocoders import Nominatim
locator = Nominatim(user_agent="myGeocoder")


@qgsfunction(args='auto', group='Custom')
def geocode(field, feature, parent):
    """
    Geocoding
    field: string field of the original layer made like 'piazza navona, rome, italy'
    
    returns a simple string of lat and long, like '43.56565 17.45454'
    """
    location = locator.geocode(field)
    lat = location.latitude
    long = location.longitude
    tot = f'{lat} {long}'
    
    return tot

OSGeo4W shell

py3_env
pip3 install geopy

@pigreco

thanks, gist updated