Python environments
Interpreters
To install different Python interpreters I strongly recommend asdf1.
Let’s look at to install Python in two different OSes, macOS and Fedora.
macOS
To install asdf on a macOS, first install the general dependencies with
$ brew install coreutils curl git
then install asdf itself with
$ brew install asdf
Add to the shell, in our case zsh with:
$ echo -e "\n. $(brew --prefix asdf)/asdf.sh" >> ~/.zshrc
Add a plugin, in our case Python, with
$ asdf plugin add Python
You can list all available versions with
$ asdf list all Python
Install a specific version, say,
$ asdf install Python 3.9.0
Fedora
To install asdf on a Fedora, first install the general dependencies
$ sudo dnf install curl git
Clone the repository
$ git clone https://github.com/asdf-vm/asdf.git \
~/.asdf --branch v0.8.0
Add to zsh with
`$ . $HOME/.asdf/asdf.sh`
pyenv
Compiling on macOS
pyenv can be notoriously problematic on macOS. For instance, running pyenv doctor on my laptop2 will result in:
Cloning ~/.pyenv/plugins/pyenv-doctor/bin/.....
Installing python-pyenv-doctor...
python-build: use readline from homebrew
python-build: use zlib from xcode sdk
BUILD FAILED (OS X 10.15.7 using python-build 20180424)
Inspect or clean up the working tree at /var/folders/c2/9d2fsqt57t10zn1f2ylp1jxw0000gn/T/python-build.20210128094523.17091
Results logged to /var/folders/c2/9d2fsqt57t10zn1f2ylp1jxw0000gn/T/python-build.20210128094523.17091.log
Last 10 log lines:
checking readline/readline.h, presence... no
checking for readline/readline.h,... no
checking readline/rlconf.h usability... yes
checking readline/rlconf.h presence... yes
checking for readline/rlconf.h... yes
checking for SSL_library_init in -lssl... no
configure: WARNING: OpenSSL <1.1 not installed. Checking v1.1 or beyond...
checking for OPENSSL_init_ssl in -lssl... no
configure: error: OpenSSL is not installed.
make: *** No targets specified and no makefile found. Stop.
Problem(s) detected while checking system.
See https://github.com/pyenv/pyenv/wiki/Common-build-problems for known solutions.
The problem in this case is that pyenv can’t find the relevant C headers for compilation of new versions. This can be fixed by using:
$ CFLAGS="-I$(brew --prefix openssl)/include \
-I$(brew --prefix readline)/include \
-I$(xcrun --show-sdk-path)/usr/include" \
LDFLAGS="-L$(brew --prefix openssl)/lib \
-L$(brew --prefix readline)/lib \
-L$(xcrun --show-sdk-path)/usr/lib" \
pyenv doctor
and the output will be:
Cloning ~/.pyenv/plugins/pyenv-doctor/bin/.....
Installing python-pyenv-doctor...
python-build: use readline from homebrew
python-build: use zlib from xcode sdk
Installed python-pyenv-doctor to /var/folders/c2/9d2fsqt57t10zn1f2ylp1jxw0000gn/T/pyenv-doctor.20210128095003.18889/prefix
Congratulations! You are ready to build pythons!
Poetry
Poetry as Jupyter kernel
To register a poetry environment (named foo) as a Jupyter kernel, run:
poetry run python -m ipykernel install --user --name foo
Hatch
Installation
To install Hatch in macOS use
brew install hatch
Hatch can also be installed with pip
pip install hatch
Or pipx for global access
pipx install hatch
venv
Create a new venv with the command:
$ virtualenv venv
Alternatively, create the virtualenv name foo in ~/.virtualenvs using
$ python -m venv ~/.virtualenvs/foo
and activate it using (under Bash or zsh) with:
$ source venv/bin/activate
Anaconda
First download Anaconda (or Miniconda). Once installed you can proceed to create environments3.
Creating environments
An environment foo can be created using
conda create --name foo
One it is created, it can be activated using
conda activate foo