Управление версиями Python. Linux/Raspberry

$ python --version
Python 2.7.13

# update-alternatives --list python

$ ls /usr/bin/python*

# update-alternatives --install /usr/bin/python python /usr/bin/python2.7 1
и 
# update-alternatives --install /usr/bin/python python /usr/bin/python3.5 2

# python --version 
Python 3.5.3

# update-alternatives --config python

https://unixhow.com/3557/kak-izmenit-versiyu-python-po-umolchaniyu-v-debian