Anybody have tips to update my python code to python 3?

Hi, my python code below does not work in python 3, I receive a " Unicode-objects must be encoded before hashing" error message. Any tips?

import sys, getopt, hashlib, os

from hashlib import sha1

import hmac

import base64

import time

import requests

import subprocess

import json

import fme

import fmeobjects

import datetime

def calculate_signature(feature):

# get input values from feature attributes

api_key = FME_MacroValues['API']

host = feature.getAttribute('host')

method = feature.getAttribute('method')

shared_secret = FME_MacroValues['SharedSecret']

timestamp = feature.getAttribute('timestamp')

#timestamp = datetime.datetime.utcnow()

url = feature.getAttribute('url')

# set access_key

#access_key = FME_MacroValues['AccessKey']

access_key = 'A0F66A0E-0CC9-7ABE-24CC-F8807E2829AB'

# copied code from calcualte_signature

sig_block = "{}\\r\\n{}\\r\\n{}\\r\\n{}\\r\\n{}\\r\\n{}\\r\\n".format(

method.upper(),

host,

url.lower(),

timestamp,

api_key,

access_key)

print("\\n\\n -- sig block -- \\n" + sig_block + "\\n\\n")

decoded_secret = base64.b64decode(shared_secret)

hashed = hmac.new(decoded_secret, sig_block, sha1)

sig = hashed.digest().encode("base64").rstrip('\\n')

# add sig value to feature as attribute

feature.setAttribute('sig',sig)

#feature.setAttribute('timestamp',str(timestamp))