>>> import hmac, hashlib
>>> res = hmac.new('signature', 'text', hashlib.sha256)
>>> res.hexdigest()
'3bd9ef87a8de4633a588904d24a64670905a3375687ae52e3daeba82dd702269'>>> hmac.new(bytearray('signature','utf-8'), bytearray('text','utf-8'), hashlib.sha256).hexdigest()
'3bd9ef87a8de4633a588904d24a64670905a3375687ae52e3daeba82dd702269'