This question is more related to python programming than using weewx, but I cant find a solution - so I hope that Tom and the other gurus can point me in the right direction.
I am writing a function to capture power consumption from the utility meter. As part of that I am storing the cumulative energy reading for each archive period in the archive. To get the incremental energy reading between archive periods I read the last archive record of the cumulative energy with the "latest" function in weewx.tags. Reading and printing the latest archive record of cumulative energy works fine - here is a snippet of the code to do that (thanks to Tom's answers to previous threads) # Create a RecordBinder, bound to the database and timestamp rb = weewx.tags.RecordBinder(db_lookup, timestamp) print "The last cumulative electrical energy record =", rb.latest().cumEnergy When I try to subtract the value for rb.latest().cumEnergy from the current cumulative energy reading just obtained from the meter, I get a type error. Then I added the following code to try and figure out what the out type of rb.latest().cumEnergy is last_cum_energy = rb.latest().cumEnergy print type(last_cum_energy) This does not help because the output of the last print command is <class 'weewx.units.ValueHelper'> I tried doing a float modification, but that does not work. Any help to turn the output of the function into something I can do arithmetic with will be appreciated. -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to weewx-user+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.