Python version manager
Sometimes it is useful to keep multiple versions of python on the same machine. Suppose for the development of two projects, we need the second and third branch of python. Or do you support a project that uses the old version of python.
Usually for this we use the virtual environment virtualenv or the wrapper for it virtualenvwrapper . I will not talk about this, as there are already many similar articles, and the documentation for the utilities themselves is very well explained. It is enough to score virtualenv or virtualenvwrapper in a search engine.
But in addition to them, I want to tell you in this article about the python version manager. Who is curious to ask under the cat.
To use multiple versions of python, you can install them manually or use the version manager. There are two such: pythonbrew (which no longer develops ) and pyenv . Both managers do not support windows ( pythonbrew , pyenv ), so that Pythonists writing on this platform will have to handle everything for the time being, or make their own utility for changing paths to the correct versions. Who can cope with this situation in the comments.
Since pythonbrew is no longer supported in this article, it will not be covered.
PS The article contains examples verified for OS Ubuntu 12.04. When you try to repeat them, make amendments regarding your distribution.
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In order to work with several versions of Python, you can install the necessary versions in the specified prefix. For example, in order not to be wise with rights, we will install an additional 2 versions of python (2.7.6 and 3.3.2) in the user directory:
2.7.6
for 3.3.2 we do the same operations:
Now you can create a virtual environment to use these versions:
or through virtualenvwrapper:
Actually, based on this method, an article on creating a multi-hosting is described.
Further, if you need to use one of these versions as python by default, then you need to add the path to the python interpreter to the environment variable.
Accordingly, instead of bashrc, you set bash_profile, zshrc, kshrc, profile depending on your command shell.
And if necessary, you can install pip , after installing setuptools .
Fuh, well, everything seems to be. And now about how to make it easier using the python version manager.
In general, if you are lazy enough, then you can not do all the things described above and use the pyenv utility, which will simplify this interaction with your environment and ways.
So what is the feature of this utility? Here's what she can according to the project author:
By default, all versions of Python will be available in
How to put pyenv well described in the instructions . Also, the author has a script that by itself pyenv puts more plug-ins, including for virtualenv . It is possible to install a plugin for virtualenvwrapper .
Before installing, you must put some dependencies :
Before you start the installation, make sure you have git installed:
Next, install the instructions :
Or so:
In the second case, the installation will happen with additional plugins.
Next, in order for everything to work, let's add our bashrc and reload the shell:
To update the utility or change its version use git.
In addition, everything is quite detailed and detailed with the author of the project in his repositories on github .
Everything, and then whatever you want. If you are using 3 python branches, then to create a virtual environment, you can use the venv utility , which works out of the box. About this there is an article on Habré. If you are more accustomed to virtualenv or its virtualenvwrapper wrapper, then there are two options: either install a plugin for pyenv , or use them for the version of python you work with. Accordingly, if you choose the first option, then the environments you created will be added to your python versions and accessible via the command:
Adding a plugin is easy, just clone it from the pyenv-virtualenv or pyenv-virtualenvwrapper repository:
An example of use can be found in the documentation for pyenv-virtualenv and pyenv-virtualenvwrapper .
All, and then use, as you like.
Now being in the project directory, you can run a script from the desired version of python without attaching any action. pyenv creates a .python-version file in the directory which contains information about which version of python with which environment to use for this project.
github.com/utahta/pythonbrew
github.com/yyuu/pyenv
github.com/yyuu/pyenv-installer
github.com/yyuu/pyenv-virtualenv
github.com/yyuu/pyenv-virtualenvwrapper
docs.python.org/dev/library/venv.html
www.virtualenv.org/en/latest
virtualenvwrapper.readthedocs.org/en/latest
Usually for this we use the virtual environment virtualenv or the wrapper for it virtualenvwrapper . I will not talk about this, as there are already many similar articles, and the documentation for the utilities themselves is very well explained. It is enough to score virtualenv or virtualenvwrapper in a search engine.
But in addition to them, I want to tell you in this article about the python version manager. Who is curious to ask under the cat.
To use multiple versions of python, you can install them manually or use the version manager. There are two such: pythonbrew (which no longer develops ) and pyenv . Both managers do not support windows ( pythonbrew , pyenv ), so that Pythonists writing on this platform will have to handle everything for the time being, or make their own utility for changing paths to the correct versions. Who can cope with this situation in the comments.
Since pythonbrew is no longer supported in this article, it will not be covered.
PS The article contains examples verified for OS Ubuntu 12.04. When you try to repeat them, make amendments regarding your distribution.
')
Manual mode
In order to work with several versions of Python, you can install the necessary versions in the specified prefix. For example, in order not to be wise with rights, we will install an additional 2 versions of python (2.7.6 and 3.3.2) in the user directory:
2.7.6
$ mkdir -p ~/python/src/ && cd ~/python/src/ $ wget http://www.python.org/ftp/python/2.7.6/Python-2.7.6.tar.xz $ tar -xf ~/python/src/Python-2.7.6.tar.xz && cd ./Python-2.7.6 $ ./configure --prefix=$HOME/python/2.7.6/ $ make && make install for 3.3.2 we do the same operations:
$ wget http://www.python.org/ftp/python/3.3.2/Python-3.3.2.tar.xz ~/python/src/ $ tar -xf ~/python/src/Python-3.3.2.tar.xz && cd ./Python-3.3.2 $ ./configure --prefix=$HOME/python/3.3.2/ $ make && make install Now you can create a virtual environment to use these versions:
$ virtualenv -p ~/python/2.7.6/bin/python env && . ./env/bin/activate or through virtualenvwrapper:
$ mkvirtualenv -p ~/python/2.7.6/bin/python evnwrapper Actually, based on this method, an article on creating a multi-hosting is described.
Further, if you need to use one of these versions as python by default, then you need to add the path to the python interpreter to the environment variable.
$ echo 'export PATH=~/python/2.7.6/bin/' >> ~/.bashrc Accordingly, instead of bashrc, you set bash_profile, zshrc, kshrc, profile depending on your command shell.
$ . ~/.bashrc And if necessary, you can install pip , after installing setuptools .
$ wget https://bitbucket.org/pypa/setuptools/raw/bootstrap/ez_setup.py -O - | python $ wget https://raw.github.com/pypa/pip/master/contrib/get-pip.py -O - | python Fuh, well, everything seems to be. And now about how to make it easier using the python version manager.
Pyenv
In general, if you are lazy enough, then you can not do all the things described above and use the pyenv utility, which will simplify this interaction with your environment and ways.
So what is the feature of this utility? Here's what she can according to the project author:
- Let you change the global Python version on a per-user basis.
- Provide support for per-project Python versions .
- Allow you to override the Python version with an environment variable.
- Search commands from multiple versions of Python at a time . This may be helpful to test across Python versions with tox .
By default, all versions of Python will be available in
~/.pyenv/versions/ . You can change Python versions both in the global context and in the local (for example, for a specific project).How to put pyenv well described in the instructions . Also, the author has a script that by itself pyenv puts more plug-ins, including for virtualenv . It is possible to install a plugin for virtualenvwrapper .
Before installing, you must put some dependencies :
# apt-get install make libssl-dev zlib1g-dev libbz2-dev libreadline-dev libsqlite3-dev Before you start the installation, make sure you have git installed:
# apt-get install git Next, install the instructions :
$ git clone git://github.com/yyuu/pyenv.git ~/.pyenv Or so:
$ curl https://raw.github.com/yyuu/pyenv-installer/master/bin/pyenv-installer | bash In the second case, the installation will happen with additional plugins.
Next, in order for everything to work, let's add our bashrc and reload the shell:
$ echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.bashrc $ echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.bashrc $ echo 'eval "$(pyenv init -)"' >> ~/.bashrc $ . ~/.bashrc To update the utility or change its version use git.
Instruction
To manage pyenv versions, go to the directory with the utility:
To view available versions:
to change version
for update
$ cd ~/.pyenv To view available versions:
$ git tag to change version
$ git checkout <version> for update
$ git pull Usage example
~ $ pyenv install 2.7.5 ~ $ pyenv install 3.3.2 ~ $ pyenv rehash ~ $ pyenv versions * system 2.7.5 3.3.2 ~ $ pyenv global 2.7.5 ~ $ python --version Python 2.7.5 ~ $ cd projects/ ~/projects $ pyenv local 3.3.2 ~/projects $ python --version Python 3.3.2 ~/projects $ cd test_prj/ ~/projects/test_prj $ python --version Python 3.3.2 ~/projects/test_prj $ cd .. ~/projects $ pyenv local --unset ~/projects $ python --version Python 2.7.5 In addition, everything is quite detailed and detailed with the author of the project in his repositories on github .
Virtual environment
Everything, and then whatever you want. If you are using 3 python branches, then to create a virtual environment, you can use the venv utility , which works out of the box. About this there is an article on Habré. If you are more accustomed to virtualenv or its virtualenvwrapper wrapper, then there are two options: either install a plugin for pyenv , or use them for the version of python you work with. Accordingly, if you choose the first option, then the environments you created will be added to your python versions and accessible via the command:
$ pyenv versions Adding a plugin is easy, just clone it from the pyenv-virtualenv or pyenv-virtualenvwrapper repository:
$ mkdir -p ~/.pyenv/plugins $ git clone git://github.com/yyuu/pyenv-virtualenv.git ~/.pyenv/plugins/pyenv-virtualenv $ git clone git://github.com/yyuu/pyenv-virtualenvwrapper.git ~/.pyenv/plugins/pyenv-virtualenvwrapper An example of use can be found in the documentation for pyenv-virtualenv and pyenv-virtualenvwrapper .
All, and then use, as you like.
Usage example
$ pyenv versions * system 2.7.5 3.3.2 $ mkdir -p ~/test_project/prj_for_2.7.5 && cd ~/test_project/prj_for_2.7.5 $ pyenv virtualenv 2.7.5 my-virtualenv-2.7.5 $ pyenv local my-virtualenv-2.7.5 $ pip install django==1.4 $ pip freeze Django==1.4 wsgiref==0.1.2 $ python --version Python 2.7.5 $ mkdir -p ~/test_project/test_project && cd ~/test_project/test_project $ pyenv virtualenv 3.3.2 my-virtualenv-3.3.2 $ pyenv local my-virtualenv-3.3.2 $ pip install django==1.5 $ pip freeze Django==1.5 $ python --version Python 3.3.2 Now being in the project directory, you can run a script from the desired version of python without attaching any action. pyenv creates a .python-version file in the directory which contains information about which version of python with which environment to use for this project.
useful links
github.com/utahta/pythonbrew
github.com/yyuu/pyenv
github.com/yyuu/pyenv-installer
github.com/yyuu/pyenv-virtualenv
github.com/yyuu/pyenv-virtualenvwrapper
docs.python.org/dev/library/venv.html
www.virtualenv.org/en/latest
virtualenvwrapper.readthedocs.org/en/latest
Source: https://habr.com/ru/post/203516/
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