A Problem of Ubuntu installation of ROS Melodic
1 sudo sh -c ‘echo “deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main” > /etc/apt/sources.list.d/ros-latest.list’
2 sudo apt-key adv –keyserver ‘hkp://keyserver.ubuntu.com:80’ –recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654
if occur “gpg: keyserver receive failed: Connection timed out “
sudo sucurl -sSL 'http://keyserver.ubuntu.com/pks/lookup?op=get&search=0xC1CF6E31E6BADE8868B172B4F42ED6FBAB17C654' | sudo apt-key add -or
gpg --keyserver 'hkp://keyserver.ubuntu.com:80' --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654B Open Anaconda Prompt (base):
- Update conda:
conda update -n base -c defaults conda- Create new environment with Python 3.8:
conda create -n python38 python=3.8- Activate your new Python 3.8 environment:
conda activate python38- Start Python 3.8:
pythonC Pip Usage
1 pip show numpy (pip3 show numpy )
pip show numpyName: numpy
Version: 1.20.1
Summary: NumPy is the fundamental package for array computing with Python.
Home-page: https://www.numpy.org
Author: Travis E. Oliphant et al.
Author-email: None
License: BSD
Location: /home/xerob/anaconda3/envs/python38/lib/python3.8/site-packages
Requires:
Required-by: scs, scipy, qdldl, osqp, matplotlib, ecos, cvxpy2 pip list (pip3 list)
pip show numpyThe showing is as follows:
Package Version
----------------------------- -------------------
actionlib 1.12.1
angles 1.9.12
bondpy 1.8.5
camera-calibration 1.15.0
camera-calibration-parsers 1.11.13
catkin 0.7.29
certifi 2020.12.5
controller-manager 0.18.3
controller-manager-msgs 0.18.3
cv-bridge 1.13.0
cvxopt 1.2.6
cvxpy 1.1.10
cycler 0.10.0
diagnostic-analysis 1.9.7
diagnostic-common-diagnostics 1.9.7
diagnostic-updater 1.9.7
dynamic-reconfigure 1.6.3
ecos 2.0.7.post1
gazebo-plugins 2.8.7
gazebo-ros 2.8.7
gencpp 0.6.5
geneus 2.2.6
genlisp 0.4.16
genmsg 0.5.16D Roscore issue
<< roscoreCommand ‘roscore’ not found, but can be installed with: sudo apt install python-roslaunch
<< sudo apt install python-roslaunchReading package lists… Done
Building dependency tree
Reading state information… Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The solution of this issue is
echo "source /opt/ros/kinetic/setup.bash" >> ~/.bashrc
source ~/.bashrcOR
echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc
source ~/.bashrc