Python repr fix for RecursionError caused by circular references in lanelets with regulatory elements

[johannes-fischer]

This MR contains some small fixes related to calling repr and str on python lanelet objects.

• when calling repr of a lanelet that contains regulatory elements with a reference back to the lanelet, you currently get

  # Traceback (most recent call last):
  #   File "<stdin>", line 1, in <module>
  # RecursionError: maximum recursion depth exceeded while calling a Python object

  This is fixed by printing only str for Lanelets in RuleParameter instead of repr, which breaks the loop

• str now returns a concise information whereas repr contains the full object description in more cases.

For some reason this is not working as expected for RuleParameterMap, as can be seen by trying to run std::cout << trafficLightRegelem->getParameters(); here. Hence, I had to add methods for the repr of the RuleParameterMap

Example code:

import os
import lanelet2
from lanelet2.projection import UtmProjector

map_file = os.path.join("src", "lanelet2", "lanelet2_maps", "res", "mapping_example.osm")
projector = UtmProjector(lanelet2.io.Origin(49, 8.4))
loadedMap = lanelet2.io.load(map_file, projector)

ll = loadedMap.laneletLayer[45014]
print(str(ll))
print(repr(ll))

reg_els = ll.regulatoryElements
print(str(reg_els))
print(repr(reg_els))

# Right of way
reg_el = reg_els[0]
print(str(reg_el))
print(repr(reg_el))
print(str(reg_el.parameters))
print(repr(reg_el.parameters))

[immel-f]

Thanks for the contribution and for discovering that bug. Could you add some small test cases to the python unit tests for the repr functions you fixed?

[johannes-fischer]

I have added some python unit tests now.