Readme
======
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pyA2L is an `ASAM MCD-2MC `__ processing
library written in Python.
If you work with ECUs, ASAP2/A2L is the contract that describes what and
how to measure or calibrate. pyA2L helps you parse once, inspect and
validate programmatically, automate checks, and export back when needed
— all from Python.
Contents
--------
- About ASAM MCD-2 MC (ASAP2)
- What pyA2L offers
- Installation
- Getting Started (Quickstart)
- Command-line usage
- Tips
- Examples
- Compatibility
- Project links
- Contributing
- Code of Conduct
- License
- Changelog / Release notes
- Acknowledgements
About ASAM MCD-2 MC (ASAP2)
---------------------------
ASAM MCD-2 MC (ASAP2) is the ASAM standard that defines the A2L
description format for ECU measurement signals and calibration
parameters. In practice, the A2L acts as a contract between ECU software
and tools so different vendors can consistently locate data in memory
and convert raw values into physical engineering units. Runtime
transport (e.g., CCP/XCP) is out of scope of the standard.
For an authoritative overview of the standard, see the ASAM page:
https://www.asam.net/standards/detail/mcd-2-mc/
What pyA2L offers
-----------------
- Parse .a2l files and persist them as compact, queryable SQLite
databases (.a2ldb) to avoid repeated parse costs.
- Programmatic access to ASAP2 entities via SQLAlchemy ORM models
(MODULE, MEASUREMENT, CHARACTERISTIC, AXIS_DESCR, RECORD_LAYOUT,
COMPU_METHOD/COMPU_TAB, UNIT, FUNCTION, GROUP, VARIANT_CODING, etc.).
- Rich inspection helpers in pya2l.api.inspect (e.g., Characteristic,
Measurement, AxisDescr, ModPar, ModCommon) to compute shapes, axis
info, allocated memory, conversions, and more.
- Creator API in pya2l.api.create to programmatically build or augment
A2L content (PROJECT, MODULE, MEASUREMENT, CHARACTERISTIC, COMPU_METHOD,
AXIS_PTS, RECORD_LAYOUT, GROUP, FUNCTION, etc.).
- Validation utilities (pya2l.api.validate) to check common ASAP2 rules
and project-specific consistency.
- Export .a2ldb content back to A2L text or JSON when needed.
- Building blocks for automation: reporting, quality gates, CI checks,
and integration with CCP/XCP workflows.
Supported ASAP2 version: 1.7.1
Why pyA2L?
----------
- Parse once, query fast: Avoid repeated parser runs by working from
SQLite.
- Powerful model: Use SQLAlchemy ORM to navigate ASAP2 entities
naturally.
- Beyond parsing: Inspect derived properties, validate consistency, and
export back to A2L.
- Automate: Integrate with CI to enforce quality gates on A2L content.
Design highlights
-----------------
- SQLite-backed storage (.a2ldb) with SQLAlchemy models
- High-level inspection helpers in ``pya2l.api.inspect``
- Creator API in ``pya2l.api.create`` for programmatic A2L generation
- Validator framework in ``pya2l.api.validate`` yielding structured
diagnostics
- Export to A2L text or JSON format
- Optional CLI (``a2ldb-imex``) for import/export tasks
Learn more about the standard at the ASAM website:
https://www.asam.net/standards/detail/mcd-2-mc/wiki/
Installation
------------
- Via ``pip``: ``shell $ pip install pya2ldb`` **IMPORTANT**:
Package-name is ``pya2ldb`` **NOT** ``pya2l``!!!
- From Github:
- Clone / fork / download `pyA2Ldb
repository `__.
Getting Started (Quickstart)
----------------------------
Parse once, work from SQLite thereafter.
Import a .a2l file and persist it as .a2ldb (SQLite):
.. code:: python
from pya2l import DB
db = DB()
session = db.import_a2l(
"ASAP2_Demo_V161.a2l",
# Optional:
# encoding="utf-8", # default is latin-1
# progress_bar=False, # silence the progress meter
# loglevel="ERROR", # also suppresses progress
)
# Creates ASAP2_Demo_V161.a2ldb in the working directory
- Open an existing .a2ldb without re-parsing:
.. code:: python
from pya2l import DB
db = DB()
session = db.open_existing("ASAP2_Demo_V161") # extension .a2ldb is implied
Query with SQLAlchemy ORM - List all measurements ordered by name with
address and data type:
.. code:: python
from pya2l import DB
import pya2l.model as model
db = DB()
session = db.open_existing("ASAP2_Demo_V161")
measurements = (
session.query(model.Measurement)
.order_by(model.Measurement.name)
.all()
)
for m in measurements:
print(f"{m.name:48} {m.datatype:12} 0x{m.ecu_address.address:08x}")
High-level inspection helpers - Use convenience wrappers from
pya2l.api.inspect to access derived info:
.. code:: python
from pya2l import DB
from pya2l.api.inspect import Characteristic, Measurement, AxisDescr
db = DB()
session = db.open_existing("ASAP2_Demo_V161")
ch = Characteristic(session, "ASAM.C.MAP.UBYTE.IDENTICAL")
print("shape:", ch.dim().shape)
print("element size:", ch.fnc_element_size(), "bytes")
print("num axes:", ch.num_axes())
me = Measurement(session, "ASAM.M.SCALAR.UBYTE.IDENTICAL")
print("is virtual:", me.is_virtual())
axis = ch.axisDescription("X")
print("axis info:", axis.axisDescription("X"))
Create A2L content programmatically - Use the Creator API to build or
augment A2L databases:
.. code:: python
from pya2l import DB
from pya2l.api.create import (
ProjectCreator, ModuleCreator, MeasurementCreator,
CharacteristicCreator, CompuMethodCreator
)
db = DB()
session = db.open_create("MyProject.a2ldb")
# Create project and module
pc = ProjectCreator(session)
project = pc.create_project("MyProject", "Demo ECU Project")
mc = ModuleCreator(session)
module = mc.create_module("MyModule", "Demo Module", project=project)
# Add a conversion method
cmc = CompuMethodCreator(session)
cm = cmc.create_compu_method(
"CM_Voltage", "Voltage conversion", "LINEAR",
"%6.3", "V", module_name="MyModule"
)
cmc.add_coeffs_linear(cm, offset=0.0, factor=0.01) # y = 0.01*x + 0
# Add a measurement
mec = MeasurementCreator(session)
meas = mec.create_measurement(
"BatteryVoltage", "Battery voltage in Volts",
"UWORD", "CM_Voltage", resolution=1, accuracy=0.1,
lower_limit=0.0, upper_limit=20.0,
module_name="MyModule"
)
mec.add_ecu_address(meas, 0x1000)
# Add a characteristic (calibration parameter)
cc = CharacteristicCreator(session)
char = cc.create_characteristic(
"InjectionMap", "Fuel injection map",
"MAP", 0x2000, "RL_InjMap", 0.0, "CM_Voltage",
0.0, 100.0, module_name="MyModule"
)
mc.commit()
db.close()
Validate your database
.. code:: python
from pya2l import DB
from pya2l.api.validate import Validator
db = DB()
session = db.open_existing("ASAP2_Demo_V161")
vd = Validator(session)
for msg in vd(): # iterate diagnostics
# msg has fields: type (Level), category (Category), diag_code (Diagnostics), text (str)
print(msg.type.name, msg.category.name, msg.diag_code.name, "-", msg.text)
Export back to A2L or JSON
.. code:: python
from pya2l import export_a2l
# Export to A2L text format
export_a2l("ASAP2_Demo_V161", "exported.a2l")
# Or export to JSON for further processing
from pya2l.imex.json_exporter import export_json
export_json("ASAP2_Demo_V161.a2ldb", "exported.json")
Tips
----
- Default import encoding is latin-1; override ``encoding=`` if your file differs.
- Silence the progress meter via ``progress_bar=False`` or ``loglevel="ERROR"``.
- Python package name is ``pya2ldb`` (not ``pya2l``).
- See `howto <./howto.rst>`__ for Excel export and other short recipes.
Examples
--------
- See ``pya2l/examples`` for sample A2L files and scripts.
- The Sphinx docs contain a fuller tutorial and HOWTO guides.
Create API and coverage parity
------------------------------
pyA2L offers a Creator API in pya2l.api.create to programmatically build
or augment A2L content. The project’s goal is coverage parity:
everything you can query via pya2l.api.inspect is intended to be
creatable via pya2l.api.create.
Example: creating common entities
.. code:: python
from pya2l import DB
from pya2l.api.create import ModuleCreator
from pya2l.api.inspect import Module
# Open or create a database
session = DB().open_create("MyProject.a2l") # or .a2ldb
mc = ModuleCreator(session)
# Create a module
mod = mc.create_module("DEMO", "Demo ECU module")
# Units and conversions
temp_unit = mc.add_unit(mod, name="degC", long_identifier="Celsius",
display="°C", type_str="TEMPERATURE")
ct = mc.add_compu_tab(mod, name="TAB_NOINTP_DEMO", long_identifier="Demo Tab",
conversion_type="TAB_NOINTP",
pairs=[(0, 0.0), (100, 1.0)], default_numeric=0.0)
# Frames and transformers
fr = mc.add_frame(mod, name="FRAME1", long_identifier="Demo frame",
scaling_unit=1, rate=10, measurements=["ENGINE_SPEED"])
tr = mc.add_transformer(mod, name="TR1", version="1.0",
executable32="tr32.dll", executable64="tr64.dll",
timeout=1000, trigger="ON_CHANGE", inverse="NONE",
in_objects=["ENGINE_SPEED"], out_objects=["SPEED_PHYS"])
# Typedefs and instances
ts = mc.add_typedef_structure(mod, name="TSig", long_identifier="Signal",
size=8)
mc.add_structure_component(ts, name="raw", typedefName="UWORD", addressOffset=0)
inst = mc.add_instance(mod, name="S1", long_identifier="Inst of TSig",
type_name="TSig", address=0x1000)
# Verify with inspect helpers
mi = Module(session)
print("#frames:", len(list(mi.frame.query())))
print("#compu tabs:", len(list(mi.compu_tab.query())))
See pya2l/examples/create_quickstart.py for a more complete example.
Command-line usage
------------------
A small CLI is provided as a console script named ``a2ldb-imex``:
.. code:: bash
# Show version
$ a2ldb-imex -V
# Import an A2L (creates .a2ldb next to the input or in CWD with -L)
$ a2ldb-imex -i path/to/file.a2l
# Import with explicit encoding and create DB in current directory
$ a2ldb-imex -i path/to/file.a2l -E latin-1 -L
# Export an .a2ldb back to A2L text (stdout by default or -o file)
$ a2ldb-imex -e path/to/file.a2ldb -o exported.a2l
Compatibility
-------------
- Python: 3.10 – 3.14
- Platforms: Prebuilt wheels are published for selected platforms. From
source, Windows/macOS are supported; Linux may require building native
extensions.
Project links
-------------
- Source code: https://github.com/christoph2/pyA2L
- Issue tracker: https://github.com/christoph2/pyA2L/issues
- PyPI: https://pypi.org/project/pya2ldb/
- `Documentation `__
Contributing
------------
Contributions are welcome! Please open an issue to discuss significant
changes before submitting a PR. See the existing tests under
``pya2l/tests`` and examples under ``pya2l/examples`` to get started.
Contributors should use pre-commit to run formatting and lint checks
before committing; see https://pre-commit.com/ for installation and
usage.
Code of Conduct
---------------
This project follows a Code of Conduct to foster an open and welcoming
community. Please read and abide by it when interacting in issues,
discussions, and pull requests.
See `CODE_OF_CONDUCT <../CODE_OF_CONDUCT.md>`__ for full details.
Changelog / Release notes
-------------------------
See GitHub Releases: https://github.com/christoph2/pyA2L/releases
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