unicode sms problem HELP

Hi, i am running a very simple sms API code from Vonage(nexmo) to send bulk sms .

Code is working fine with normal text but when i try to send in Greek ( Cyrilic alphabet ) i get jiberish text like : " ????? ????? ???? " sign that unicode is not automatically activated in the code .I have tried "pip install unicode " then "import unicode" but pycharm error says can't find module named unicode i have tried to "type": unicode , but error that no module unicode istalled 

Here is my code : 

import csv
import vonage

client = vonage.Client(key="226xxxx", secret="Dg9xxxxxxx")
sms = vonage.Sms(client)


def get_mobile_nos_from_csv_file():
    with open('data.csv') as csvfile:
        mobile_nos = []
        reader = csv.DictReader(csvfile)
        for row in reader:
            mobile_nos.append(row['mobile'])

        print("collected All Mobile No's From Csv File !!!")
        return mobile_nos


def send_msg_to_mobile_no(mobile, msg="Wελcομε το Ζιμα Hοτελ Ζακιντοσ"):
    print("sending msg to mobile %s msg %s" % (mobile, msg))
    responseData = sms.send_message(
        {
            "from": "Zima Hotel",
            "to": str(mobile),
            "text": msg,
        }
    )

    if responseData["messages"][0]["status"] == "0":
        print("Msg to %s  sent successfully." % (str(mobile)))
    else:
        print(f"Message to {str(mobile)} failed with error: {responseData['messages'][0]['error-text']}")


# Press the green button in the gutter to run the script.
if __name__ == '__main__':
    mobile_nos = get_mobile_nos_from_csv_file()

    for mobile in mobile_nos:
        send_msg_to_mobile_no(mobile)