iso8583 - a Python package for parsing ISO8583 data

iso8583 package serializes and deserializes ISO8583 data between raw bytes ISO8583 data and a regular Python dict.

iso8583 package supports custom specifications that can define:

• Field length and data encoding, such as BCD, ASCII, EBCDIC, etc.
• Field length count measured in bytes or nibbles.
• Field type, such as fixed, LLVAR, LLLVAR, etc.
• Maximum length
• Optional field description

Multiple specifications can co-exist to support ISO8583 messages for POS, ATM, file actions, and so on. Simply define a new specification dictionary. iso8583 package includes a starter specification in iso8583.specs module that can be used as a base to create own custom/proprietary specifications.

Additional information is available on Read The Docs.

Installation

iso8583 is published on PyPI as pyiso8583 and can be installed from there:

pip install pyiso8583

Encoding & Decoding

Use iso8583.decode to decode raw ISO8583 message. It returns two dictionaries: one with decoded data and one with encoded data.

>>> import pprint
>>> import iso8583
>>> from iso8583.specs import default_ascii as spec
>>> encoded_raw = b'02004000000000000000101234567890'
>>> decoded, encoded = iso8583.decode(encoded_raw, spec)
>>> pprint.pp(decoded)
{'t': '0200', 'p': '4000000000000000', '2': '1234567890'}
>>> pprint.pp(encoded)
{'t': {'len': b'', 'data': b'0200'},
 'p': {'len': b'', 'data': b'4000000000000000'},
 '2': {'len': b'10', 'data': b'1234567890'}}

Modify the decoded message to send a response back. Change message type from '0200' to '0210'. Remove field 2 (PAN). And add field 39 (Response Code).

>>> decoded['t'] = '0210'
>>> decoded.pop('2', None)
'1234567890'
>>> decoded['39'] = '05'

Use iso8583.encode to encode updated ISO8583 message. It returns a raw ISO8583 message and a dictionary with encoded data.

>>> encoded_raw, encoded = iso8583.encode(decoded, spec)
>>> encoded_raw
bytearray(b'0210000000000200000005')
>>> pprint.pp(decoded)
{'t': '0210', 'p': '0000000002000000', '39': '05'}
>>> pprint.pp(encoded)
{'t': {'len': b'', 'data': b'0210'},
 'p': {'len': b'', 'data': b'0000000002000000'},
 '39': {'len': b'', 'data': b'05'}}

Pretty Print Messages

Use iso8583.pp to pretty print ISO8583 message.

>>> import iso8583
>>> from iso8583.specs import default_ascii as spec
>>> encoded_raw = b'02004000000000000000101234567890'
>>> decoded, encoded = iso8583.decode(encoded_raw, spec)
>>> iso8583.pp(decoded, spec)
t   Message Type                  : '0200'
p   Bitmap, Primary               : '4000000000000000'
2   Primary Account Number (PAN)  : '1234567890'
>>> iso8583.pp(encoded, spec)
t   Message Type                  : b'0200'
p   Bitmap, Primary               : b'4000000000000000'
2   Primary Account Number (PAN)  : b'10' b'1234567890'

Contribute

iso8583 package is hosted on GitHub.

Feel free to fork and send contributions over.