os_uptime incorrect on 4.0.0/python3.7 on macos

[Graham Eddy]

having moved to 4.0.0/python3.7 last night i see a couple of anomalies i did not notice in testing.

the following one is mainly cosmetic but i think i have a fix for it

uptime_os (in the “About Station” part of Season skin) presently reports obviously incorrect value:

Server uptime	18393 days, 0 hours, 10 minutes
WeeWX uptime	0 days, 8 hours, 35 minutes
WeeWX version	4.0.0

looking in weewx/station.py:

try:

    # For MacOs:

    from Quartz.QuartzCore import CACurrentMediaTime

    os_uptime_secs = CACurrentMediaTime()

except ImportError:

a simple test shows the ImportError option is being exercised:

from Quartz.QuartzCore import CACurrentMediaTime

os_uptime_secs = CACurrentMediaTime()

print(os_uptime_secs)

print(os_uptime_secs/float(3600))

and python3.7 (from macports) gives

Traceback (most recent call last):

  File "/Users/graham/a.py", line 1, in <module>

    from Quartz.QuartzCore import CACurrentMediaTime

ModuleNotFoundError: No module named 'Quartz'

but python2.7 (from macos platform), where 3.9.1 worked fine, gives

815589.697895

226.55269386

reading weewx/station.py, the consequence of following the Import exception is that os_uptime_secs remains unset i.e. a garbage value

unfortunately i can’t install the missing module Quartz under python3.7:

sudo python3.7 -m pip install Quartz

Password:

...

Collecting Quartz

  Downloading quartz-0.0.1.dev0.tar.gz (217 kB)

     |████████████████████████████████| 217 kB 694 kB/s 

    ERROR: Command errored out with exit status 1:

...

      File "/private/tmp/pip-install-36vqysll/Quartz/setup.py", line 7, in read_dependencies

        with open(req_file) as req:

    FileNotFoundError: [Errno 2] No such file or directory: 'requirements.txt'

consulting doctor google, i came across module uptime, which i installed using python3.7 -m pip.

purportedly  it is cross-platform including linux and linux-like. it seems to give the correct result for macos and, if it really is cross-platform, could simplify weewx/station.py by avoiding testing for each platform itself

import uptime

secs = uptime.uptime()

print(secs)

print(secs/float(3600))

gives good values on my mac server:

817999.84659

227.22217960833333

but it is a dependency on another external module

g-eddy

[Tom Keffer]

It is a new dependency, which is unacceptable, especially for such a minor feature.

Looking through the source code for 'uptime', on Python 2 it uses the module MacOS, but under Python 3, it relies on custom ctypes code.

If we can't find a way around this, we're just going to have to disable the Mac system uptime tag.

-tk

--
You received this message because you are subscribed to the Google Groups "weewx-development" group.
To unsubscribe from this group and stop receiving emails from it, send an email to weewx-developm...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-development/8F61A89F-8268-464F-96EA-245700B03B62%40gmail.com.

[Greg Troxel]

Tom Keffer <tke...@gmail.com> writes:

> If we can't find a way around this, we're just going to have to disable the
> Mac system uptime tag.

Perhaps initialize uptime, before any code is run, to None to mean "we
don't know", and then just omit reading/using it when None, which could
handle systems that can't get uptime in general.

[Tom Keffer]

Exactly. A PR from someone is welcome.

-tk