To retrieve the service provider (carrier) name of a phone number in Python, use the carrier module from the phonenumbers library. First, parse the phone number string using phonenumbers.parse(), then call carrier.name_for_number() with the parsed object.

import phonenumbers
from phonenumbers import carrier

number = "+country code phonenumber"
parsed_number = phonenumbers.parse(number, "RO")
print(carrier.name_for_number(parsed_number, "en"))