To prove I'm alive, record it today. Python2 question and 3 of this switch.
python3.xx popularity, after you install linux python3, but some software does not support the total error. so I have to find a compromise. Install two versions of the software error if the switch version.
A open terminal are input the following two commands:
update-alternatives --install /usr/bin/python python /usr/bin/python2 100
update-alternatives --install /usr/bin/python python /usr/bin/python3 150
Second, then open an input terminal
python --version
Third, if you need to switch python version:
update-alternatives --config python
Fourth, python and then choose the version you need, enter the serial number on it. If you need to switch back to the python version:
update-alternatives --config python (Pick)