tango-pyaml

Bridge between Tango Controls and PyAML

Overview

tango-pyaml is a Python bridge between the Tango control system and the PyAML abstraction layer for control systems. It provides a set of classes that allow Tango attributes and devices to be accessed and controlled using PyAML concepts.

This library is part of the Python Accelerator Middle Layer (PyAML) ecosystem.

Features

• ✅ Read and write Tango attributes via a unified PyAML interface
• 🔁 Support for read-only and read/write attributes
• 📊 Grouped attribute operations using tango.Group
• 💥 Exception mapping from Tango exceptions to PyAML exceptions
• 🧹 Designed to integrate seamlessly with PyAML ControlSystem components
• 🧪 Mocked devices for unit testing without Tango runtime

Installation

pip install tango-pyaml

Requirements

• Python >= 3.9
• PyTango >= 9.5.1
• PyAML
• pydantic >= 2.0

For development and testing:

pip install tango-pyaml[dev]

Usage Example

This is an example of an explicit call to a Tango attribute using PyAML. For more details about implicit declaration and broader configuration options, please refer to the PyAML documentation.

Configuration file attribute.yaml:

attribute: "sys/tg_test/1/float_scalar"
unit: "A"

Python code:

from tango.pyaml.attribute import Attribute
from tango.pyaml.tango_attribute import ConfigModel
import yaml

with open("attribute.yaml") as f:
    cfg_dict = yaml.safe_load(f)

cfg = ConfigModel(**cfg_dict)
attr = Attribute(cfg)

attr.set(10.0)
value = attr.get()
readback = attr.readback()

print(f"Value: {value}, Readback: {readback.value} [{readback.quality}]")

Available Classes

• Attribute — Read/write access to a Tango attribute
• AttributeReadOnly — Read-only attribute wrapper
• AttributeList — Manage a group of attributes from multiple devices
• TangoControlSystem — Adapter to configure global Tango control system context

Testing

Tests rely on mocked Tango devices and attributes using unittest.mock. To run tests:

pytest

Project Structure

• tango.pyaml.attribute – Main attribute interface
• tango.pyaml.attribute_read_only – Read-only attribute implementation
• tango.pyaml.attribute_list – Attribute groups with tango.Group
• tango.pyaml.tango_attribute – Base class wrapping attribute logic
• mocked_device_proxy.py – In-memory mock for Tango DeviceProxy and AttributeProxy

License

This project is licensed under the MIT License.

Links

• 🧺 Repository