Use bytes for strings

Author: pipermerriam

ethereum/utils.py

@@ -110,7 +110,8 @@ def int_to_32bytearray(i):
 def sha3(seed):
     sha3_count[0] += 1
     return sha3_256(to_string(seed))
-assert sha3('').encode('hex') == 'c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470'
+
+assert encode_hex(sha3('')) == b'c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470'
 
 
 def privtoaddr(x, extended=False):