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pyA2L is an ASAM MCD-2MC <https://www.asam.net/standards/detail/mcd-2-mc/>__ 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
• C++ parser (ANTLR4-based) for fast parsing (2.5 MB/s)
• Adaptive flush strategy automatically tunes performance (10% speedup for large files)
• 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 with complete roundtrip fidelity
• Optional CLI (a2ldb-imex) for import/export tasks
• Concurrent access via SQLite WAL mode (multiple readers during export)

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 <https://github.com/christoph2/pya2l>__.

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",