brip
stands for Brython's pip.
It brings the Python packages ecosystem and the pip-like workflow to Brython-powered projects.
You can use brip
to install packages from the PyPI and other indexes, into your different Brython project.
- Historically, most brython-oriented Python packages are pre-compiled into - and distributed as - a javascript file. This works well for those self-contained Python packages, but when/if a Python package has its own dependencies, there was no obvious way to declare and manage those dependencies.
- In general, there was no Pythonic way to install a generic Python package and their dependencies, directly from PyPI into your Brython project.
brip
is developed to bring the PyPI ecosystem and the familiar pip-like workflow
to Brython-powered projects.
There is a complete sample project, Easter,
to demonstrate how to use brip
.
Just run pip install brip
.
It is recommended that you install brip
into one central virtual environment,
rather than installing brip
inside each of your brython project's environment.
(In fact, your Brython project technically does not need its own virtual environment.)
Installation on Linux and macOS:
python3 -m venv ~/venv_central
source ~/venv_central/bin/activate
pip install brip
Installation on Windows:
py -m venv $HOME\venv_central
$HOME\venv_central\Scripts\activate.bat
pip install brip
This manual assumes you use Linux or macOS. Windows users please adjust the path separator in each sample.
-
Install a package from PyPI into your Brython project's web root directory (i.e. the directory containing your
index.html
):cd my_brython_project_one/website brip install SomePackage
Now a new
site-packages.brython.js
is generated in current directory, containing SomePackage and its dependencies. Your Brython project'sindex.html
would just need to add a line<script src="site-packages.brython.js"></script>
, from now on you can useimport some_package
inside your Brython project!Package installed by
brip
is obtained directly from PyPI. You do NOT need to install the package bypip
first. -
List what packages are installed for current Brython project (or more precisely speaking, list packages contained in
site-packages.brython.js
):cd my_brython_project_one/website brip list
Note: Packages installed by
brip
are not visible topip list
, and vice versa. Because their installation target are completely different. -
Install several packages from PyPI into your Brython project's web root directory (i.e. the directory containing your
index.html
):cd my_brython_project_two/website brip install -r brequirements.txt
The file "brequirements.txt" has a format identical to
pip
's "requirements.txt", and it can be named whatever name you want. We recommend using a name different than pip's conventional "requirements.txt", though, such as "brequirements.txt", to remind you that its content are meant to be installed bybrip
, not bypip
. -
Uninstalling a package ... is not directly supported, but can be achieved by organizing your full dependency list in a "brequirements.txt" file, and then use this pattern:
cd my_brython_project_two/website # Use your editor to remove one package name edit brequirements.txt # Each install will OVERWRITE existing site-packages.brython.js brip install -r brequirements.txt
In pip
you can do incremental installation.
If you run pip install foo
and then pip install bar
,
you would end up with both foo
and bar
installed.
But, due to some technical reason, brip
always do overwrite installation.
If you run brip install foo
and then brip install bar
,
you would end up with only bar
available in your Brython project.
Therefore, we recommend you always use a "brequirements.txt"
to organize your project's full dependency.
That way, any adjustment to such a file would be flushed to your Brython project
by next brip install -r brequirements.txt
.
brip
also only implements a small subset of pip
.
Please refer to the command-line help brip -h
or brip install -h
etc..
brip
aims to bring the entire Python Package Index (PyPI) ecosystem to Brython.
However, in reality there are some limitations outside of the control of brip
.
-
Brython-powered applications are running inside a browser. The browser is a capable virtual machine in its own right. However, many Python packages are not expected to be run inside a browser. For example, file system behaves differently in Brython: Writing is impossible, and reading is limited to the folders accessible with an Ajax request.
-
Brython itself only supports pure Python packages. That excludes packages which are partially written in C, such as
numpy
. Consequently, only those packages written in pure Python and its entire dependency chain written in pure Python, would work in Brython. -
As of this writing, Brython 3.10.5 does not support converting namespace packages into a loadable javascript file.
-
Sometimes, even pure Python package might not work in Brython, due to some subtle differences between Brython and CPython.
-
Unfortunately, there is currently no straightforward way to know whether a Python package would work in Brython. You probably have to rely on trial-and-error. Just use
brip
to install a package, use it in Brython environment, and see if the browser console logs any error.
Feel free to report those packages into
brip's issue list.
brip
might not be in position to solve it directly,
but the community might be able to help.
While we mentioned in the Problem Statement that brip
was mainly developed to
allow Brython app developers to pull generic Python packages from PyPI, for example:
# Inside the brequirements.txt, it contains the following line
charts.css.py>=0.4,<1
there is nothing wrong for a self-contained, Brython-friendly package to be distributed as a javascript file, for example:
<!-- Inside the index.html, it contains the following line -->
<script src='https://github.com/rayluo/charts.css.py/releases/download/0.4.0/charts.css.py-brython.js'></script>
Here, the term "Brython-friendly" is defined as a generic, pure Python package that can be released to PyPI, but it is also designed to be able to work in Brython.
So, how do you - a Brython-friendly package's maintainer - generate that javascript file?
Here is how I pack my package
charts.css.py
into a charts.css.py-brython.js
:
cd charts.css.py
brip install .
# Now a site-packages.brython.js is generated in current directory,
# containing the PyPI-ready project in current directory.
# I just need to rename it to charts.css.py-brython.js and distribute it.
While doing so, you may see a warning message on your console:
DEPRECATION: A future pip version will change local packages to be built in-place without first copying to a temporary directory. We recommend you use --use-feature=in-tree-build to test your packages with this new behavior before it becomes the default.
pip 21.3 will remove support for this functionality. You can find discussion regarding this at https://github.com/pypa/pip/issues/7555.
You can just ignore that message. It has no negative impact to your javascript outcome.
That warning message is expected to be gone once pip 21.3 becomes available
and you upgrade to it (by running python -m pip install --upgrade pip
).