problem when I put my code in service on linux, doesnt write csv file

Question

I dont know why, when I put on service on linux, this program doesnt save on csv file.

with open('file.csv', mode='w', newline='') as csv_file:
    fieldnames = ['Timestamp', 'IP Address', 'Port']
    writer = csv.DictWriter(csv_file, fieldnames=fieldnames)
    writer.writeheader()
    time = datetime.datetime.now().strftime('%y-%m-%d %H:%M:%S')
    while True:
        client_socket, client_address = server_socket.accept()
        print('IP: ',client_address[0], 'Porta: ', client_address[1], 'Data: ', time)
        writer.writerow({'Timestamp': time,
                         'IP Address': client_address[0],
                         'Port': client_address[1]})
        client_socket.close()