python syntax errors in __init__.py,core.py,temporal_algebra.py

[Chris Hermansen]

Installing QGIS 3.12.2 using apt after an upgrade from 19.10 to 20.04 I receive the following messages re package grass-core:

Setting up grass-core (7.8.2-1build3) ...
/usr/lib/grass78/etc/python/grass/pygrass/gis/__init__.py:75: SyntaxWarning: "is" with a literal. Did you mean "=="?
  if value is '':
/usr/lib/grass78/etc/python/grass/temporal/core.py:65: SyntaxWarning: "is" with a literal. Did you mean "=="?
  if do_profiling is "True" or do_profiling is "1":
/usr/lib/grass78/etc/python/grass/temporal/core.py:65: SyntaxWarning: "is" with a literal. Did you mean "=="?
  if do_profiling is "True" or do_profiling is "1":
/usr/lib/grass78/etc/python/grass/temporal/core.py:582: SyntaxWarning: "is not" with a literal. Did you mean "!="?
  if driver_string is not None and driver_string is not "":
/usr/lib/grass78/etc/python/grass/temporal/temporal_algebra.py:2295: SyntaxWarning: "is" with a literal. Did you mean "=="?
  if map_i.get_type() is "raster" or map_i.get_type() is "raster3d":
/usr/lib/grass78/etc/python/grass/temporal/temporal_algebra.py:2295: SyntaxWarning: "is" with a literal. Did you mean "=="?
  if map_i.get_type() is "raster" or map_i.get_type() is "raster3d":

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: grass-core 7.8.2-1build3
ProcVersionSignature: Ubuntu 5.4.0-28.32-generic 5.4.30
Uname: Linux 5.4.0-28-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Wed Apr 29 15:41:54 2020
InstallationDate: Installed on 2019-04-24 (371 days ago)
InstallationMedia: Ubuntu 19.04 "Disco Dingo" - Release amd64 (20190416)
SourcePackage: grass
UpgradeStatus: Upgraded to focal on 2020-04-28 (1 days ago)

[Markus Neteler (neteler)]

I believe that this has been addressed in

https://github.com/OSGeo/grass/pull/540

(not yet backported from master to 7.8 release branch)

[Chris Hermansen (c-hermansen)]

I looked at description of fixes at

https://github.com/OSGeo/grass/pull/540

and I don't see anything referring to the warnings.

However, looking at the first warning .../__init__.py:75, on my computer, the offending line is

    if value is '':

whereas the version on GitHub is

    if value == '':

which I suppose would correct the warning, and surely must be the intended code.

So let's hope the backport arrives soon!

[Markus Neteler (neteler)]

As per https://github.com/OSGeo/grass/pull/540#issuecomment-622991997:

The issues are fixed in master and backported to 7.8: https://github.com/OSGeo/grass/pull/264

It will be part of GRASS GIS 7.8.3, to be released in the next days.