Difference between revisions of "Python deployments"
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| − | Hynek Schlawack | + | == 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> | ||
| + | <source lang="bash"> | ||
| + | cd | ||
| + | mkdir environments | ||
| + | cd environments/ | ||
| + | pyvenv my_env | ||
| + | source my_env/bin/activate | ||
| + | pip install --upgrade pip | ||
| + | pip install soundscrape | ||
| + | pip install soundscrape --upgrade | ||
| + | soundscrape https://soundcloud.com/pianoman_weddings/coldplay | ||
| + | </source> | ||
| + | </ref> | ||
| + | |||
| + | Hynek Schlawack (from 2013) | ||
* [https://hynek.me/talks/python-deployments/ Notes] | * [https://hynek.me/talks/python-deployments/ Notes] | ||
* [https://www.youtube.com/watch?v=RvbDCzroavY Video] | * [https://www.youtube.com/watch?v=RvbDCzroavY Video] | ||
== Python Packaging == | == Python Packaging == | ||
| − | + | In the old days (2015) there were still debates about how to package Python and install stuff. Now, it's settled. Use pip. Easy_install is dead. See the [https://docs.python.org/3/installing/index.html docs]. Also note that <code>venv</code> is the successor to <code>virtualenv</code> | |
| − | https:// | + | |
| + | == 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</code> to help prevent any potential confusion as to which Python interpreter a 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 | ||
| + | # maybe upgrade pip | ||
| + | pip install --upgrade pip | ||
| + | # then install your local environment packages | ||
| + | pip 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. | ||
| + | |||
| + | It is best to use a virtual environment which isolates packages for you. That way you can play around without polluting the global python install. | ||
| + | |||
| + | As a bonus, virtualenv does not need elevated permissions. | ||
| + | |||
| + | * Installing a package is as simple as <code>pip install foo</code> | ||
| + | * Upgrades are <code>pip install --upgrade foo</code> | ||
| + | * <code>pip uninstall foo</code> if you want to remove foo | ||
| − | + | {{References}} | |
[[Category:Python]] | [[Category:Python]] | ||
Latest revision as of 09:46, 26 March 2024
Contents
Check Python[edit | edit source]
Check the version of the default Python interpreter:
python --version
List the versions of python available:
ls /usr/bin/python*
Use update-alternatives to setup system-wide ability to choose Python interpreter. The one with the higher priority number will become the default.
update-alternatives --install /usr/bin/python python /usr/bin/python2.7 1
update-alternatives --install /usr/bin/python python /usr/bin/python3.6 2
Now we can list the choices:
update-alternatives --list python
And choose one:
update-alternatives --config python
We can also remove a choice if it's no longer an option on the system:
update-alternatives --remove python /usr/bin/python2.7
Python Virtual Environments[edit | edit source]
See Digital Ocean's quick guide to setting up a local Python programming environment, including virtual environments, which is what I did for SoundScrape Btw, SoundScrape is a neat tool to download sound files from SoundCloud. [1]
Hynek Schlawack (from 2013)
Python Packaging[edit | edit source]
In the old days (2015) there were still debates about how to package Python and install stuff. Now, it's settled. Use pip. Easy_install is dead. See the docs. Also note that venv is the successor to virtualenv
Basic PIP and Virtual Environments[edit | edit source]
Do NOT (normally) use sudo with pip. Use a virtual environment. As of Python 3.4, the command is now called pyvenv or simply venv. As of Python 3.6 pyvenv is deprecated in favor of using python3 -m venv to help prevent any potential confusion as to which Python interpreter a 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 Ansible Playbook Grapher
python3.11 -m venv myenv
# .. some output ..
source myenv/bin/activate
# maybe upgrade pip
pip install --upgrade pip
# then install your local environment packages
pip install what-i-want
# done using this python?
deactivate
You only use sudo or elevated permissions when you want to install stuff for the global, system-wide Python installation.
It is best to use a virtual environment which isolates packages for you. That way you can play around without polluting the global python install.
As a bonus, virtualenv does not need elevated permissions.
- Installing a package is as simple as
pip install foo - Upgrades are
pip install --upgrade foo pip uninstall fooif you want to remove foo
References[edit source]
- ↑
cd mkdir environments cd environments/ pyvenv my_env source my_env/bin/activate pip install --upgrade pip pip install soundscrape pip install soundscrape --upgrade soundscrape https://soundcloud.com/pianoman_weddings/coldplay
