As you're writing code for WeeWX, whether it's a search list extension, a new service, or a driver, it's useful to get in the habit of checking whether a value could be None. It's how WeeWX signals that a datum is missing or bad.
Almost surely this is the problem with your template. As Gary said, look for all the minus signs then think hard about whether one of the operands could be None. While you're at it, check all the other operators! -tk On Tue, May 8, 2018 at 6:26 PM, John Smith <[email protected]> wrote: > > > On Wednesday, 9 May 2018 11:00:51 UTC+10, Thomas Keffer wrote: >> >> In theory you can use the Cheetah compiler >> <https://pythonhosted.org/Cheetah/users_guide/gettingStarted.html#the-cheetah-command> >> to precompile your template to a file. Then you can see the line numbers. >> But, I've found it frustrating to use and tend to follow Gary's suggestions. >> >> One useful technique is to use the Cheetah #breakpoint >> <https://pythonhosted.org/Cheetah/users_guide/parserInstructions.html#breakpoint> >> command. It's quicker and easier than deleting sections of your code. >> > > The big problem is it's intermittent for Greg, and I can't reproduce the > problem. > > -- > 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 [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- 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 [email protected]. For more options, visit https://groups.google.com/d/optout.
