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== Check Python ==
Check the version of the default Python interpreter:
<code>python --version</code>
 
List the versions of python available:
<code>ls /usr/bin/python*</code>
 
Use <code>update-alternatives</code> to setup system-wide ability to choose Python interpreter. The one with the '''higher''' priority number will become the default.<br>
<code>update-alternatives --install /usr/bin/python python /usr/bin/python2.7 1</code><br>
<code>update-alternatives --install /usr/bin/python python /usr/bin/python3.6 2</code>
 
Now we can list the choices:
<code>update-alternatives --list python</code>
 
And choose one:
<code>update-alternatives --config python</code>
 
We can also remove a choice if it's no longer an option on the system:
<code>update-alternatives --remove python /usr/bin/python2.7</code>
 
== Python Virtual Environments ==
See Digital Ocean's quick guide to [https://www.digitalocean.com/community/tutorials/how-to-install-python-3-and-set-up-a-local-programming-environment-on-ubuntu-16-04 setting up a local Python programming environment], including [https://virtualenv.pypa.io/en/stable/ virtual environments], which is what I did for [https://github.com/Miserlou/SoundScrape SoundScrape] Btw, SoundScrape is a neat tool to download sound files from SoundCloud.
<ref>
== Basic PIP and Virtual Environments ==
Do NOT (normally) use sudo with pip. Use a virtual environment. As of Python 3.4, the command is now called <code>pyvenv</code> or simply <code>venv</code>. As of Python 3.6 <code>pyvenv</code> is '''deprecated''' in favor of using <code>python3 -m venv</codcode> to help prevent any potential confusion as to which Python interpreter a vritual virtual environment will be based on.'''python3''' is not generic. It represents the '''exact''' version you wish to use in your virtual environment. As an example, I needed to create a Python Virtual Environment to use the [https://github.com/freephile/meza/issues/63#issuecomment-2020431602 Ansible Playbook Grapher]
<source lang="bash">
$ python3 .11 -m venv myenv# .. some output ..$ source myenv/bin/activate(myenv) $ # maybe upgrade pippip install --upgrade pip# then install your local environment packagespip install what-i-want
# done using this python?
deactivate
</source>
 
You only use sudo or elevated permissions when you want to install stuff for the global, system-wide Python installation.