hashes.hamming_code

Hamming codes are a family of linear error-correcting codes. Hamming codes can detect up to two-bit errors or correct one-bit errors without detection of uncorrected errors. By contrast, the simple parity code cannot correct errors, and can detect only an odd number of bits in error. Hamming codes are perfect codes, that is, they achieve the highest possible rate for codes with their block length and minimum distance of three.

  • the implemented code consists of:
    • a function responsible for encoding the message (emitterConverter)

      • return the encoded message

    • a function responsible for decoding the message (receptorConverter)

      • return the decoded message and a ack of data integrity

  • how to use:

    to be used you must declare how many parity bits (sizePari)

    you want to include in the message.

    it is desired (for test purposes) to select a bit to be set

    as an error. This serves to check whether the code is working correctly.

    Lastly, the variable of the message/word that must be desired to be

    encoded (text).

  • how this work:

    declaration of variables (sizePari, be, text)

    converts the message/word (text) to binary using the

    text_to_bits function

    encodes the message using the rules of hamming encoding decodes the message using the rules of hamming encoding print the original message, the encoded message and the

    decoded message

    forces an error in the coded text variable decodes the message that was forced the error print the original message, the encoded message, the bit changed

    message and the decoded message

Functions

emitter_converter(size_par, data)

receptor_converter(size_par, data)

text_from_bits(bits[, encoding, errors])

text_to_bits(text[, encoding, errors])

Module Contents

hashes.hamming_code.emitter_converter(size_par, data)
Parameters:

  • size_par – how many parity bits the message must have

  • data – information bits

Returns:

message to be transmitted by unreliable medium - bits of information merged with parity bits

>>> emitter_converter(4, "101010111111")
['1', '1', '1', '1', '0', '1', '0', '0', '1', '0', '1', '1', '1', '1', '1', '1']
>>> emitter_converter(5, "101010111111")
Traceback (most recent call last):
    ...
ValueError: size of parity don't match with size of data
hashes.hamming_code.receptor_converter(size_par, data)
>>> receptor_converter(4, "1111010010111111")
(['1', '0', '1', '0', '1', '0', '1', '1', '1', '1', '1', '1'], True)
hashes.hamming_code.text_from_bits(bits, encoding='utf-8', errors='surrogatepass')
>>> text_from_bits('011011010111001101100111')
'msg'
hashes.hamming_code.text_to_bits(text, encoding='utf-8', errors='surrogatepass')
>>> text_to_bits("msg")
'011011010111001101100111'