select_for_sampling
===================
**Source code:** `select_for_sampling.py <https://chromium.googlesource.com/chromiumos/platform/factory/+/refs/heads/main/py/test/pytests/select_for_sampling.py>`_

Decide if this device is selected for certain sampling tests.

Description
-----------
For some sampling tests, the tests should only be run for a subset of
DUTs by a given sampling rate. This test uses a hash of the WLAN MAC
address (wlan0 or mlan0) to decide if we should sample this device or
not, and writes a "True" or "False" to the device data with the
(optionally) specified key.

Test Procedure
--------------
This is an automated test without user interaction.

Dependency
----------
Need the device to have a WiFi interface with non-fixed MAC address.

Examples
--------
To select about 10% of the devices and mark devices selected as
'selected_for_sampling' in device data, add this in test list::

  {
    "pytest_name": "select_for_sampling",
    "args": {
      "rate": 0.1
    }
  }

To select about 20% of the devices, and mark using 'run_audio' key::

  {
    "pytest_name": "select_for_sampling",
    "args": {
      "rate": 0.2,
      "device_data_key": "run_audio"
    }
  }


Test Arguments
--------------
.. list-table::
   :widths: 20 10 60
   :header-rows: 1
   :align: left

   * - Name
     - Type
     - Description

   * - rate
     - float
     - Sampling rate (0 to never select any devices, 1 to select all, 0.2 to select 20% of devices, etc.)

   * - device_data_key
     - str
     - (optional; default: ``'selected_for_sampling'``) Key in the device data dictionary