Cloud9 may be used for Python development, but by default the Python3 interpreter is 3.4.3. You can check the Python3 version by running the following command in a new terminal window:

python3 --version

To install a more recent version of Python3, visit and identify the specific release you want to install. The following terminal commands install Python 3.6.8.

tar xzvf Python-3.6.8.tgz
cd Python-3.6.8
./configure --with-ssl
sudo make install
cd ..
sudo rm -rf Python-3.6.8
rm Python-3.6.8.tgz

sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.4 1
sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.5 2
sudo update-alternatives --install /usr/bin/python3 python3 /usr/local/bin/python3.6 3
sudo update-alternatives --set python3 /usr/local/bin/python3.6

Then configure Cloud9 Python Support:

  1. Open Preferences
  2. Select Python Support
  3. Change Python Version to Python 3
  4. Add :/usr/local/lib/python3.6/dist-packages to the end of the Python path
  5. Close Preferences

Test the Python version from a terminal window:

python3 --version

Test the Python version with a new Python program:

import sys