Problem converting to python3

[Daniel Rich]

WeeWX 4.1.0

Installed via. package manager

I figured I would try and get my station up and running with 4.1 and python3 today, but ran into a problem. For some reason, the aqi extension (https://github.com/jonathankoren/weewx-aqi) can't find the calculator module if I switch /etc/default/weewx to use WEEWX_PYTHON=python3. Even after installing the needed modules and fixing the purpleair plugin (simple fixes, adding "as" to exceptions and adding parens to one print call) I get:

May 28 14:37:20 weather weewx[3267] INFO __main__: Initializing weewx version 4.1.0

May 28 14:37:20 weather weewx[3267] INFO __main__: Using Python 3.5.3 (default, Sep 27 2018, 17:25:39) #012[GCC 6.3.0 20170516]

May 28 14:37:20 weather weewx[3267] INFO __main__: Platform Linux-4.19.57-v7+-armv7l-with-debian-9.11

May 28 14:37:20 weather weewx[3267] INFO __main__: Locale is 'en_US.UTF-8'

May 28 14:37:20 weather weewx[3267] INFO __main__: PID file is /var/run/weewx.pid

May 28 14:37:20 weather weewx[3271] INFO __main__: Using configuration file /etc/weewx/weewx.conf

May 28 14:37:20 weather weewx[3271] INFO __main__: Debug is 0

May 28 14:37:20 weather weewx[3271] INFO weewx.engine: Loading station type Vantage (weewx.drivers.vantage)

May 28 14:37:20 weather weewx[3254]: Starting weewx weather system: weewx.

May 28 14:37:20 weather weewx[3271] INFO weewx.engine: StdConvert target unit is 0x1

May 28 14:37:20 weather weewx[3271] INFO weewx.wxservices: The following values will be calculated: pressure=prefer_hardware, altimeter=prefer_hardware, appTemp=prefer_hardware, barometer=prefer_hardware, beaufort=prefer_hardware, cloudbase=software, dewpoint=prefer_hardware, ET=prefer_hardware, heatindex=prefer_hardware, humidex=prefer_hardware, inDewpoint=prefer_hardware, maxSolarRad=software, rainRate=prefer_hardware, windchill=prefer_hardware, windrun=prefer_hardware

May 28 14:37:20 weather weewx[3271] INFO weewx.wxservices: The following algorithms will be used for calculations: altimeter=aaASOS, maxSolarRad=RS

May 28 14:37:21 weather weewx[3271] CRITICAL __main__: Caught unrecoverable exception:

May 28 14:37:21 weather weewx[3271] CRITICAL __main__:     ****  No module named 'calculators'

May 28 14:37:21 weather weewx[3271] CRITICAL __main__:     ****  Traceback (most recent call last):

May 28 14:37:21 weather weewx[3271] CRITICAL __main__:     ****    File "/usr/share/weewx/weewxd", line 148, in main

May 28 14:37:21 weather weewx[3271] CRITICAL __main__:     ****      engine = weewx.engine.StdEngine(config_dict)

May 28 14:37:21 weather weewx[3271] CRITICAL __main__:     ****    File "/usr/share/weewx/weewx/engine.py", line 75, in __init__

May 28 14:37:21 weather weewx[3271] CRITICAL __main__:     ****      self.loadServices(config_dict)

May 28 14:37:21 weather weewx[3271] CRITICAL __main__:     ****    File "/usr/share/weewx/weewx/engine.py", line 138, in loadServices

May 28 14:37:21 weather weewx[3271] CRITICAL __main__:     ****      obj = weeutil.weeutil.get_object(svc)(self,config_dict)

May 28 14:37:21 weather weewx[3271] CRITICAL __main__:     ****    File "/usr/share/weewx/weeutil/weeutil.py", line 1093, in get_object

May 28 14:37:21 weather weewx[3271] CRITICAL __main__:     ****      mod = __import__(module)

May 28 14:37:21 weather weewx[3271] CRITICAL __main__:     ****    File "/usr/share/weewx/user/aqi/service.py", line 15, in <module>

May 28 14:37:21 weather weewx[3271] CRITICAL __main__:     ****      import calculators

May 28 14:37:21 weather weewx[3271] CRITICAL __main__:     ****  ImportError: No module named 'calculators'

May 28 14:37:21 weather weewx[3271] CRITICAL __main__:     ****  Exiting.

Any idea why it can't find that module? I see  it in /usr/share/weewx/user/aqi/calculators.py, and it imports correctly under python2. Even reinstalling the aqi extension after making the switch to python3 doesn't help. Is there something different in the way the module path is set in python 3.x?

The module itself loads fine in both python2 and python3 if I manually force the path:

> python2

Python 2.7.13 (default, Sep 26 2018, 18:42:22)

[GCC 6.3.0 20170516] on linux2

Type "help", "copyright", "credits" or "license" for more information.

>>> import sys

>>> sys.path.append('/usr/share/weewx/user/aqi')

>>> import calculators

>>> ^C

> python3

Python 3.5.3 (default, Sep 27 2018, 17:25:39)

[GCC 6.3.0 20170516] on linux

Type "help", "copyright", "credits" or "license" for more information.

>>> import sys

>>> sys.path.append('/usr/share/weewx/user/aqi')

>>> import calculators

>>> ^C