Hallöchen!
Peter Hansen <[EMAIL PROTECTED]> writes:
> Torsten Bronger wrote:
>
>> keithley = GpibInstrument(14)
>> keithley.write("*IDN?")
>> print keithley.read()
>>
>> A keithley.close() would be a wart in my opinion; instead I want
>> to hide the whole session thing from the programmer. Besides, I
>> haven't yet given up the hope that the issues with __del__ can be
>> tackled.
>
> At least one alternative comes to mind. Have the GpibInstrument
> class (or its module) register an atexit() method, and have the
> constructor for that class track all instances. On shutdown, the
> atexit method goes through all instruments that are still open and
> issues the .close() requests, or whatever you do in the __del__
> now.
However, this doesn't close sessions while the program is running.
If the programmer has the above code in a function which is called
repeatedly, he may run into trouble. IIRC my current VISA DLL has
only 256 session slots.
Tschö,
Torsten.
--
Torsten Bronger, aquisgrana, europa vetus
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