Transitioning from the conda
or mamba
to pixi
#
Welcome to the guide designed to ease your transition from conda
or mamba
to pixi
.
This document compares key commands and concepts between these tools, highlighting pixi
's unique approach to managing environments and packages.
With pixi
, you'll experience a project-based workflow, enhancing your development process, and allowing for easy sharing of your work.
Why Pixi?#
Pixi
builds upon the foundation of the conda ecosystem, introducing a project-centric approach rather than focusing solely on environments.
This shift towards projects offers a more organized and efficient way to manage dependencies and run code, tailored to modern development practices.
Key Differences at a Glance#
Task | Conda/Mamba | Pixi |
---|---|---|
Installation | Requires an installer | Download and add to path (See installation) |
Creating an Environment | conda create -n myenv -c conda-forge python=3.8 |
pixi init myenv followed by pixi add python=3.8 |
Activating an Environment | conda activate myenv |
pixi shell within the project directory |
Deactivating an Environment | conda deactivate |
exit from the pixi shell |
Running a Task | conda run -n myenv python my_program.py |
pixi run python my_program.py (See run) |
Installing a Package | conda install numpy |
pixi add numpy |
Uninstalling a Package | conda remove numpy |
pixi remove numpy |
No base
environment
Conda has a base environment, which is the default environment when you start a new shell.
Pixi does not have a base environment. And requires you to install the tools you need in the project or globally.
Using pixi global install bat
will install bat
in a global environment, which is not the same as the base
environment in conda.
Activating pixi environment in the current shell
For some advanced use-cases, you can activate the environment in the current shell.
This uses the pixi shell-hook
which prints the activation script, which can be used to activate the environment in the current shell without pixi
itself.
Environment vs Project#
Conda
and mamba
focus on managing environments, while pixi
emphasizes projects.
In pixi
, a project is a folder containing a manifest(pixi.toml
/pyproject.toml
) file that describes the project, a pixi.lock
lock-file that describes the exact dependencies, and a .pixi
folder that contains the environment.
This project-centric approach allows for easy sharing and collaboration, as the project folder contains all the necessary information to recreate the environment. It manages more than one environment for more than one platform in a single project, and allows for easy switching between them. (See multiple environments)
Global environments#
conda
installs all environments in one global location.
When this is important to you for filesystem reasons, you can use the detached-environments feature of pixi.
pixi config set detached-environments true
# or a specific location
pixi config set detached-environments /path/to/envs
pixi shell -n
but it will make the installation of the environments go to the same folder.
pixi
does have the pixi global
command to install tools on your machine. (See global)
This is not a replacement for conda
but works the same as pipx
and condax
.
It creates a single isolated environment for the given requirement and installs the binaries into the global path.
Never install pip
with pixi global
Installations with pixi global
get their own isolated environment.
Installing pip
with pixi global
will create a new isolated environment with its own pip
binary.
Using that pip
binary will install packages in the pip
environment, making it unreachable form anywhere as you can't activate it.
Automated switching#
With pixi
you can import environment.yml
files into a pixi project. (See import)
environment.yml
file.
Troubleshooting#
Encountering issues? Here are solutions to some common problems when being used to the conda
workflow:
- Dependency
is excluded because due to strict channel priority not using this option from: 'https://conda.anaconda.org/conda-forge/'
This error occurs when the package is in multiple channels.pixi
uses a strict channel priority. See channel priority for more information. pixi global install pip
, pip doesn't work.pip
is installed in the global isolated environment. Usepixi add pip
in a project to installpip
in the project environment and use that project.pixi global install <Any Library>
->import <Any Library>
->ModuleNotFoundError: No module named '<Any Library>'
The library is installed in the global isolated environment. Usepixi add <Any Library>
in a project to install the library in the project environment and use that project.