Add a convenience func to retrieve the internal attr. hist.

A new function that can be imported to read the internal attribute history. The history is conveniently converted to a numpy.array.

What is missing: I could also extract the time stamps but did not know how to add that to the retrieved array. Could be done later.

lib/get_internal_attribute_history.py

+#! /usr/bin/env python3
+
+
+from tango import DeviceProxy
+from numpy import array, transpose
+
+
+def get_internal_attribute_history(device: DeviceProxy, attribute_name: str, depth: int = 10):
+    try:
+        history = array(device.attribute_history(attr_name = attribute_name, depth = depth))
+    except Exception as e:
+        raise ValueError("An exception was raised when attempting to access the internal history of the attribute '{}/{}'.".format(device.name(), attribute_name)) from e
+
+    history_values = array([entry.value for entry in history])
+    history_values_transposed = history_values.transpose()
+    values = array([vals for vals in history_values_transposed])
+    return values

[Jan David Mol]

"An exception was raised when" is already implicit by raising the exception. Parties logging the exception might prepend that. Can we just remove that here and go for something like "Cannot access the internal history..."?

[Thomas Juerges]

Yeah, indeed. What was I thinking.

[Jan David Mol]

please change to values = array(list(history_values_transposed)) (assuming we really do have to go through a list here, isnt it all happy numpy wonderland already?)

[Thomas Juerges]

Will do and yes, it is hopefully all numpy.array already. But then I have learned that numpy sometimes does things in odd ways and wanted to be explicit. On second thought this could be a leftover from when I still had this function to just retrieve the rcu_temperature_r history. I'll look into it and get back to you about it.