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SMS PDU encoding and decoding, including GSM-0338 character set

Project description

SMS PDU encoding and decoding, including GSM-0338 character set.


This library handles SMS-DELIVER and SMS-SUBMIT format PDUs, and includes full support for all data formats, flags and headers, and round-trips from PDU to object and back again.

It also includes convenience APIs for constructing new PDUs from text or data.

This library is very mature - it’s been in production use for many years before the 1.0 release was made. It’s also, as far as I’m aware, the most complete SMS PDU encoding and decoding library available.

The T39 functionality has been copied from the previous PyPI package with the same name as this library to provide some continuity. It is untested.

PDU Interface

Typical usage will involve the SMS_SUBMIT and SMS_DELIVER .fromPDU(), .toPDU() and .create() methods:

>>> from smspdu import SMS_SUBMIT
>>> pdu = SMS_SUBMIT.create('sender', 'recipient', 'hello, world')
>>> pdu.toPDU()
>>> pdu = smspdu.SMS_SUBMIT.fromPDU(_, 'sender')
>>> pdu.user_data
u'hello, world'

Command-line Usage

To decode a PDU on the command-line (using python2.7+), use:

% python -m smspdu 010010D0F2F2380D4F97DD7400000CE8329BFD6681EE6F399B0C

tp_mti = 1 (SMS-SUBMIT)
sender = unknown
tp_rd = 0
tp_vpf = 0
tp_vp = None
tp_rp = 0
tp_udhi = 0
tp_srr = 0
tp_mr = 0
tp_al = 16
tp_toa = d0 (Alphanumeric; Unknown)
(recipient) address = 'recipient'
tp_pid = 0x00 (Normal Case)
tp_dcs = 0x00 (Immedate Display, GSM-0338 Default Alphabet)
tp_udl = 12
tp_ud = '\xe82\x9b\xfdf\x81\xeeo9\x9b\x0c'
datestamp = 11062712173200
user_data = u'hello, world'
user_data_headers = []

The first line re-displays the PDU with the various sections colourised.

Users of versions of Python 2.6 will need to run “python -m smspdu.pdu”.

SMS Text - Handling the Awesomeness of GSM 0338

First the basics; encoding some text:

>>> from smspdu import gsm0338
>>> c = gsm0338()
>>> gsm_message = c.encode(u'test message')

And decoding that message:

>>> from smspdu import gsm0338
>>> c = gsm0338()
>>> c.decode(gsm_message)
u'test message'

The library also provides some functions for making text SMS-happy:


A simplistic function which just replaces any characters in the unicode input. You should probably use attempt_encoding instead since it tries to make the message appear the same.


Attempt to encode the supplied text for SMS transmission in a single message. This will alter the message to replace accents and typography where necessary to reduce the per-character septet count.


Used by attempt_encoding to remove all accents from characters in the supplied text.


Used by attempt_encoding to replaced typograpically-correct punctuation with simplified GSM-0338 characters.


Removes all non-printable, non-ASCII codes in the string.


Attempt to convert the SMPP data coding scheme (SMPP v34) to a useful SMS PDU (GSM 03.38) data coding scheme.

Version History (in Brief)

  • 1.0 the initial release based on mature internal code

This code is copyright 2011 Inc ( See the end of the source file for the license of use.

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