Thanks for your answer. After the command you suggested I obtain this result:
Could not find a version that satisfies the requirement yaml (from versions: )
No matching distribution found for yaml.
I also send this command: sudo pip install rospkg
Requirement already satisfied: rospkg in /usr/lib/python2.7/dist-packages
Requirement already satisfied: PyYAML in /usr/lib/python2.7/dist-packages (from rospkg)
Other ascertainment into the manual "Launch Blockly web interface"
$ cd ~/blockly_ws
$ source devel_isolated/setup.bash
$ roslaunch turtlebot3_blockly turtlebot3_blockly.launch
On the second line to find the setup.bash i must modified this line to :
It seems that all the files are present but not into the good directory! yalm for example.
The script does not go to the good directory rocon_python_utils which is present with yalm.
I do not understand why the are so many differences. Versions problems ?
Happy to read you again.