I don't think this will catch float('nan'), which is how I was bit this
time.
val = float('nan')
>>> isinstance(val, (float, int))
True
>>>
>>> type(val)
<type 'float'>
May I recommend as an alternative, slightly more robust solution:
def addSum(self, val, weight=1):
"""Add a scalar value to my running sum and count."""
if val is not None:
+ if (not isinstance(val, (float, int))) or (math.isnan(val)):
+ raise ValueError("accum: Expected float or int, got %s" %
val)
self.sum += val
self.count += 1
self.wsum += val * weight
On Monday, November 20, 2017 at 4:16:56 PM UTC-7, Tom Keffer wrote:
>
> Implemented at commit 40d7a2c
> <https://github.com/weewx/weewx/commit/40d7a2c4cd921489664e3110c29f6256e26c7ae0>
> .
>
> -tk
>
> On Mon, Nov 20, 2017 at 4:45 PM, gjr80 <[email protected] <javascript:>>
> wrote:
>
>> Well I am embarrased to say that to say I did not know about nan/NaN and
>> python, today's lesson I guess.
>>
>> Gary
>>
>> On Tuesday, 21 November 2017 01:30:57 UTC+10, Thomas Carlin wrote:
>>>
>>> Tom,
>>> Your interpretation is exactly correct, and yes it is a coding error on
>>> my side. My thought was just a single sentence there about the Weewx
>>> engine not doing any sanitation, and that being the responsibility of the
>>> driver. If not, no worries, just a thought.
>>>
>>> Gary,
>>> No worries on the delay. You got me going in the right direction, and
>>> we got it figured out! It's not like you get paid for doing this. Until
>>> yesterday, the extent of the sanitation that I was doing on the incoming
>>> data was running float(data), and catching any ValueError exception. Now,
>>> because nan is a special 'string', when you run float('nan'), it returns
>>> NaN, but now it is the Python 'number' NaN. When you add a number to NaN,
>>> your result is always NaN. When this is stuffed into the database,
>>> apparently it is interpreted as SQL NULL. Next time the loop runs, Python
>>> queries the database, and interprets SQL NULL as None, and then we get the
>>> type mismatch.
>>>
>>> I have added some more sanitation for this, and we are back up and
>>> running, and it *should* conform to expected behavior.
>>>
>>> Does that make sense?
>>>
>>> Thank you for the input on the driver. I have a laundry list of things
>>> that I would like to add to make it more robust, and I'll add the loop
>>> output to that. I may be converting to a queue as well, simply due to the
>>> number of sensors that are being polled, and the "couple of seconds" note
>>> in the Second Datasource section of the docs. But that is a project for
>>> another day!
>>>
>>> --
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