gsmcodecs 1.0.0

Python codecs for 3GPP TS 23.038

gsmcodecs

Python codecs for 3GPP TS 23.038, as used in SMS PDU.

This module provides the GSM default 7-bit alphabet and language-specific shift tables as python codecs. A particular pairing of locking shift and single shift table is chosen by appending the relevant national language IDs to a base codec 'gsm23.038', separated by dashes (-). Eg:

• gsm23.038-0-2: GSM default alphabet with Spanish single shift table

Note: These codecs encode and decode one septet per encoded octet. For GSM style septet packing, refer to related PDU utilities.

Usage

>>> import gsmcodecs
>>> 'Buenos días'.encode('gsm23.038-0-2')
b'Buenos d\x1bias'
>>> b'Buenos d\x1bias'.decode('gsm23.038-0-2')
'Buenos días'

Exported Codecs

• gsm23.038-0-0: GSM 7 bit default alphabet w/ GSM 7 bit default alphabet extension table
• gsm23.038-X-Y: National language ID X locking shift table w/ National language ID Y single shift table
• gsm23.038: Alias of gsm23.038-0-0

Note: All possible pairings of locking and single shift tables will return a codec. In the case that a chosen language ID/table is not defined, a GSM default table will be substituted. For example, gsm23.038-2-2 is technically invalid since there is no locking shift table defined for the Spanish language, the returned codec would be equivalent to gsm23.038-0-2.

National Language IDs

The following national language IDs and character mappings are recognised. Refer to 3GPP TS 23.038, section 6.2 and Annex A:

ID	National Language	Type	Table
0	Default	GSM default	6.2.1
0	Default	Single shift	6.2.1.1
1	Turkish	Locking shift	A.3.1
1	Turkish	Single shift	A.2.1
2	Spanish	Single shift	A.2.2
3	Portugese	Locking shift	A.3.3
3	Portugese	Single shift	A.2.3
4	Bengali	Locking shift	A.3.4
4	Bengali	Single shift	A.2.4
5	Gujarati	Locking shift	A.3.5
5	Gujarati	Single shift	A.2.5
6	Hindi	Locking shift	A.3.6
6	Hindi	Single shift	A.2.6
7	Kannada	Locking shift	A.3.7
7	Kannada	Single shift	A.2.7
8	Malayalam	Locking shift	A.3.8
8	Malayalam	Single shift	A.2.8
9	Oriya	Locking shift	A.3.9
9	Oriya	Single shift	A.2.9
10	Punjabi	Locking shift	A.3.10
10	Punjabi	Single shift	A.2.10
11	Tamil	Locking shift	A.3.11
11	Tamil	Single shift	A.2.11
12	Telugu	Locking shift	A.3.12
12	Telugu	Single shift	A.2.12
13	Urdu	Locking shift	A.3.13
13	Urdu	Single shift	A.2.13

CSV source files for each table are located under the 'lut/' directory.

Re-building Character Maps

Character maps for each of the default and national language tables can be re-computed from the source CSV files in the lut directory:

$ cd lut
$ make clean && make

Installation

$ pip install gsmcodecs