pyais

library3.1.0pypypi✓ verified 86d ago

A Python library for decoding and encoding AIS (Automatic Identification System) messages used in maritime navigation. Current version 3.0.0 (released 2024) with ~35% faster performance, requires Python >=3.9. No regular release cadence; version 2.x was stable for years.

communication data serialization

pip install pyais

github ↗package ↗

INSTALL

IMPORT

SIG · PYAIS

pyais

communicationpythonv3.1.0

Install

1.7s avg

Import

232ms

Disk

17MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v3.1.0 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.95 runs

installs and imports cleanly · install 0.0s · import 0.250s · 18.8MB

glibc

py 3.10–3.95 runs

installs and imports cleanly · install 1.7s · import 0.214s · 19MB

17MB installed

● package 17MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

decode

✓ from pyais import decode

✗ from pyais.decode import decode

decode is a top-level function, not a submodule. Wrong import raises ModuleNotFoundError.

AISSentence

✓ from pyais import AISSentence

✗ from pyais.messages import AISSentence

AISSentence is exported from pyais; accessing submodule path may break or not exist.

Payload

✓ from pyais import Payload

✗ from pyais.payload import Payload

Payload is a top-level export. Direct submodule import may fail.

Decode a single AIS message from an NMEA 0183 sentence.

from pyais import decode # NMEA 0183 AIS message string msg = "!AIVDM,1,1,,A,133m@ogP00PD;88MD5MTDww@2D7k,0*46" decoded = decode(msg) print(decoded) print(decoded.asdict())

Debug

Known issues

breakingv3.0.0 renamed AISSentence.bit_array to AISSentence.bv and Payload.from_bitarray() to Payload.from_vector(), Payload.to_bitarray() to Payload.to_bytes(). Code using old names will break.

fix

Replace .bit_array with .bv, .from_bitarray() with .from_vector(), .to_bitarray() with .to_bytes().

affects: <3.0.0

breakingv3.0.0 removed the bitarray dependency; replaced with custom bit_vector. Imports like 'from bitarray import bitarray' may not work for pyais internals.

fix

Do not rely on bitarray for pyais objects; use pyais's built-in bit vector.

affects: >=3.0.0

deprecatedNonPrintableCharacterException has been deprecated in v3.0.0 and may be removed in future.

fix

Catch generic Exception or use pyais's custom exceptions; avoid relying on NonPrintableCharacterException.

affects: >=3.0.0

gotchadecode() can raise pyais.exceptions.DecodingError if the message is malformed or checksum fails. New users may not handle exceptions.

fix

Wrap decode() in try/except or validate checksum separately using pyais.checksum.

affects: all

Errors

Common errors & fixes

ModuleNotFoundError: No module named 'pyais.decode'

Importing decode as a submodule instead of top-level function.

fix

Use 'from pyais import decode'.

AttributeError: 'AISSentence' object has no attribute 'bit_array'

Using deprecated attribute from v2.x. In v3.0.0, 'bit_array' was renamed to 'bv'.

fix

Replace 'bit_array' with 'bv'.

TypeError: decode() missing 1 required positional argument: 'sentence'

Calling decode on a list or forgetting to pass the sentence string.

fix

Ensure you pass a single NMEA sentence string to decode().

Upgrade

Version history

3.1.0latest on PyPI · released Jun 6, 2026

Audit

Dependencies

No dependency data recorded yet.

Agent activity

23 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/M0r13n/pyais ↗

packagehttps://pypi.org/project/pyais/ ↗