hash block python

from:
https://en.bitcoin.it/wiki/Block_hashing_algorithm

this python code will calculate the hash of the block with the smallest hash as of June 2011, Block 125552. The header is built from the six fields described above, concatenated together as little-endian values in hex notation:

 >>> import hashlib
  >>> header_hex = ("01000000" +
    "81cd02ab7e569e8bcd9317e2fe99f2de44d49ab2b8851ba4a308000000000000" +
    "e320b6c2fffc8d750423db8b1eb942ae710e951ed797f7affc8892b0f1fc122b" +
    "c7f5d74d" +
    "f2b9441a" +
     "42a14695")
  >>> header_bin = header_hex.decode('hex')
  >>> hash = hashlib.sha256(hashlib.sha256(header_bin).digest()).digest()
  >>> hash.encode('hex_codec')
  '1dbd981fe6985776b644b173a4d0385ddc1aa2a829688d1e0000000000000000'
  >>> hash[::-1].encode('hex_codec')
  '00000000000000001e8d6829a8a21adc5d38d0a473b144b6765798e61f98bd1d'