Python encoded message with HMAC-SHA256

If you want to execute in python3 you should do the following:

#python 3
import hmac
import hashlib

nonce = 1
customer_id = 123456
API_SECRET = 'thekey'
api_key = 'thapikey'

message="{} {} {}".format(nonce, customer_id, api_key)

signature = hmac.new(
    bytes(API_SECRET, 'latin-1'), 
    msg=bytes(message, 'latin-1'), 
    digestmod=hashlib.sha256
).hexdigest().upper()
print(signature)