clase_como_funcion.py

from urllib.request import urlopen

def plantilla_url(plantilla):
    def abrir(**kwargs):
        return urlopen(plantilla.format_map(kwargs))

    return abrir


clima = plantilla_url('https://samples.openweathermap.org/data/2.5/forecast?id={id}&appid=b1b15e88fa797225412429c1c50c122a1')
for linea in clima(id='524901', appid='b1b15e88fa797225412429c1c50c122a1'):
    print(linea.decode('utf-8'))