Cannot decode reading of 'None' for gauge 'windDir'

[Andrej B.]

Good afternoon,

I use Bootstrap theme with Nick gauges (dajda.net). Weewx ver. 4.1 under python 2.7 (Debian Buster)
In my syslog every archive interval I see hundreds messages like: GaugeGenerator: Cannot decode reading of 'None' for gauge 'windDir'
This is only happens when wind speed is not None. Below is logfile part:

Jun 24 19:00:15 weewxpi weewxd: GaugeGenerator: outTemp reading = 25.5 degree_C
Jun 24 19:00:15 weewxpi weewxd: GaugeGenerator: inTemp reading = 24.1111111111 degree_C
Jun 24 19:00:15 weewxpi weewxd: GaugeGenerator: barometer reading = 1022.58763232 mbar
Jun 24 19:00:15 weewxpi weewxd: GaugeGenerator: outHumidity reading = 49.0 percent
Jun 24 19:00:15 weewxpi weewxd: GaugeGenerator: inHumidity reading = 56.0 percent
Jun 24 19:00:16 weewxpi weewxd: GaugeGenerator: windSpeed reading = 2.68224 meter_per_second
Jun 24 19:00:16 weewxpi weewxd: GaugeGenerator: windGust reading = 6.25856 meter_per_second
Jun 24 19:00:16 weewxpi weewxd: GaugeGenerator: windDir reading = 0.0 degree_compass
Jun 24 19:00:16 weewxpi weewxd: GaugeGenerator: Cannot decode reading of 'None' for gauge 'windDir'
Jun 24 19:00:16 weewxpi weewxd: GaugeGenerator: Cannot decode reading of 'None' for gauge 'windDir'
Jun 24 19:00:16 weewxpi weewxd: GaugeGenerator: Cannot decode reading of 'None' for gauge 'windDir'

This is part of code responsible for this:

try:
            history = int(plot_options.get('history'))
        except:
            pass
        else:
            history_list = []
            windspeed_history_list = []

            batch_records = self.db_manager.genBatchRecords(self.lastGoodStamp - history * 60 * 60, self.lastGoodStamp)

            for rec in batch_records:
                db_value_tuple = weewx.units.as_value_tuple(rec, columnname)
                history_value = weewx.units.convert(db_value_tuple, target_unit)[0]

                try:
                    history_list.append(float(history_value))
                except:
                    syslog.syslog(syslog.LOG_DEBUG, "GaugeGenerator: Cannot decode reading of '%s' for gauge '%s'"
                                  % (history_value, gaugename))


Why this happens when wind speed has reading?

Thanks

[Andrej B.]

If wind speed is 0, then "cannot decode" message is not seen:

Jun 24 22:20:16 weewxpi weewxd: GaugeGenerator: windSpeed reading = 0.0 meter_per_second
Jun 24 22:20:16 weewxpi weewxd: GaugeGenerator: windGust reading = 0.0 meter_per_second
Jun 24 22:20:16 weewxpi weewxd: GaugeGenerator: windDir has no reading (None)
Jun 24 22:20:16 weewxpi weewxd: GaugeGenerator: radiation reading = 0.0 watt_per_meter_squared
Jun 24 22:20:16 weewxpi weewxd: GaugeGenerator: UV reading = 0.0 uv_index

[Pat]

I'm not the maintainer of this extension, and I don't use it so I'm purely guessing here.  

But based on the information you've given, try replacing the section you've pasted with this. Maintain a backup copy in case you need to revert back. 

try:
            history = int(plot_options.get('history'))
        except:
            pass
        else:
            history_list = []
            windspeed_history_list = []


            batch_records = self.db_manager.genBatchRecords(self.lastGoodStamp - history * 60 * 60, self.lastGoodStamp)


            for rec in batch_records:
                db_value_tuple = weewx.units.as_value_tuple(rec, columnname)
                history_value = weewx.units.convert(db_value_tuple, target_unit)[0]


                try:

                    if history_value is not None:
                        history_list.append(float(history_value))
                    else:
                        continue

                except:
                    syslog.syslog(syslog.LOG_DEBUG, "GaugeGenerator: Cannot decode reading of '%s' for gauge '%s'"
                                  % (history_value, gaugename))

[Andrej B.]

Hello,

Thanks. Look like this improvement works!

Andrej