Some problem while creating my catkin workspace and generating data

[Gaben21]

First problem: When running the script in the nvisii_data_gen: python single_video_pybullet.py --nb_frames 1 --scale 0.01 --nb_distractors 0 I encountered a warning:

          lsf@lsf:~/lsf_ws/src/dope/scripts/nvisii_data_gen$ python single_video_pybullet.py --nb_frames 1 --scale 0.01 -- 
          nb_distractors 0
          pybullet build time: Nov 28 2023 23:51:11
          folder output/output_example// exists
          00000/00001
          /home/lsf/lsf_ws/src/dope/scripts/nvisii_data_gen/utils.py:1126: RuntimeWarning: invalid value encountered in cast
          visible_object_ids = np.unique(segmentation_mask.astype(int))

Second problem: When installing ROS and creating my catkin workspace, I run the code(my OS is ubuntu 18.04LTS): rosdep install --from-paths src -i --rosdistro melodic then it has a problem

          lsf@lsf:~/lsf_ws$ rosdep install --from-paths src -i --rosdistro melodic
          ERROR: the following rosdeps failed to install
          pip: pip is not installed

I would appreciate any guidance on resolving this error or suggestions on what I may have missed during the setup process.

Thank you