[python] Fix a few problems with the Python exercises due to API updates of...

[python] Fix a few problems with the Python exercises due to API updates of example-robot-data and LMPC-walking. Improve plot readibility using shorter labels.
10 jobs for devel in 16 minutes and 37 seconds (queued for 1 second)
Status Name Job ID Coverage
  Test
passed doc-coverage #122455

00:16:36

39.0%
failed format #122456
allowed to fail

00:00:13

passed robotpkg-py-tsid-py2-18.04-release #122448

00:08:50

passed robotpkg-py-tsid-py3-16.04-release #122447

00:10:12

passed robotpkg-py-tsid-py3-18.04-release #122449

00:10:42

passed robotpkg-py-tsid-py3-20.04-release #122450

00:11:04

passed robotpkg-py-tsid-py3-buster-release #122451

00:12:19

passed robotpkg-py-tsid-py3-ferrum-release #122452

00:10:55

passed robotpkg-py-tsid-py3-stretch-release #122453

00:13:36

passed robotpkg-tsid-18.04-release #122454

00:03:35

 
Name Stage Failure
failed
format Test
./demo/demo_romeo.py:160:63: E231 missing whitespace after ','
./demo/demo_romeo.py:161:40: E228 missing whitespace around modulo operator
./demo/demo_romeo.py:161:69: E231 missing whitespace after ','
./demo/demo_romeo.py:162:45: E228 missing whitespace around modulo operator
./demo/demo_romeo.py:168:1: W293 blank line contains whitespace
./demo/demo_romeo.py:169:9: E228 missing whitespace around modulo operator
./demo/demo_romeo.py:175:1: W293 blank line contains whitespace
Cleaning up file based variables
ERROR: Job failed: exit code 1