What Is task_handle of nidaqmx.task in Python?

Issue Details

>>> nidaqmx.Task()
Task (name=_unnamedTask<C>)

However, inside callback_method of register_done_event(callback_method), instead of above, I am rather getting an integer value in the task_handle variable, eg: 1844437056.

>>> task_handle
1844437056

So, what is this task_handle variable and how is it related to task?

Solution

>>> def callback(task_handle, status, callback_data): 
>>>     return 0

_handle is unique integer identifier which is assigned to each task when it is created. task_handle attribute of callback method contains the handle of the task which is calling that callback method.

To access handle of a particular task object (for ex. task1, access _handle attribute of that object), following code stores handle of task1 in variable task1_handle :

>>> task1_handle = task1._handle