How to use non-installable modules from DAG code? - python-3.x

I have a Git repository which (among other things) holds Airflow DAGs in airflow directory. I have a clone of the repository besides an install directory of Airflow. airflow directory in Git is pointed to by AIRFLOW_HOME configuration variable.
I would like to allow imports from modules in the repository that are listed outside airflow folder (please see the structure below).
<repo root>
|_airflow
|_dags
|_dag.py
|_module1
|_module2
|_...
So that in dag.py I can do:
from module1 import Module1
Currently, it does not seem possible without tricks like editing sys.path explicitly which is not very elegant and has to be done in each of the dag source files...
Making an installable package out of the module1 is also out of the question.

Re-writing conclusion from discussions here
Broadly, there are 2 possible ways
Package your code into an Airflow plugin
Make your code discoverable to dag-definition-file(s) parsing processes by updating PYTHONPATH. Here again we have following options
(a) Update PYTHONPATH on system level using bashrc / equivalent (once-and-for-all) or just export the updated PYTHONPATH for current bash session
(b) Programmatically update sys.path in the beginning of DAG-definition file

Related

Relative imports within a git repo

I want to create a git repo that can be used like this:
git clone $PROJECT_URL my_project
cd my_project
python some_dir/some_script.py
And I want some_dir/some_script.py to import from another_dir/some_module.py.
How can I accomplish this?
Some desired requirements, in order of decreasing importance to me:
No sys.path modifications from within any of the .py files. This leads to fragility when doing IDE-powered automated refactoring.
No directory structure changes. The repo has been thoughtfully structured.
No changes to my environment. I don't want to add a hard-coded path to my $PYTHONPATH for instance, as that can result in unexpected behavior when I cd to other directories and launch unrelated python commands.
Minimal changes to the sequence of 3 commands above. I don't want a complicated workflow, I want to use tab-completion for some_dir/some_script.py, and I don't want to spend keystrokes on extra python cmdline flags.
I see four solutions to my general problem described here, but none of them meet all of the above requirements.
If no solution is possible, then why are things this way? This seems like such a natural want, and the requirements I list seem perfectly reasonable. I'm aware of a religious argument in a 2007 email from Guido:
I'm -1 on this and on any other proposed twiddlings of the __main__
machinery. The only use case seems to be running scripts that happen
to be living inside a module's directory, which I've always seen as an
antipattern. To make me change my mind you'd have to convince me that
it isn't.
But not sure if things have changed since then.
Opinions haven't changed on this topic since Guido's 2007 comment. If anything, we're moving even further in the opposite direction, with the additions of PYTHONSAFEPATH var and corresponding -P option in 3.11:
https://docs.python.org/3/using/cmdline.html#envvar-PYTHONSAFEPATH
https://docs.python.org/3/using/cmdline.html#cmdoption-P
These options will nerf direct sibling module imports too, requiring sys.path to be explicitly configured even for scripts!
So, scripts still can't easily do relative imports, and executable scripts living within a package structure are still considered an anti-pattern. What to do instead?! The widely accepted alternative here is to use the packaging feature of entry-points. One type of entry-point group in packaging metadata is the "console_scripts" group, used to point to arbitrary callables defined within your package code. If you add entries in this group within your package metadata, then script wrappers for those callables will be auto-generated and put somewhere on $PATH at pip install time). No hacking of sys.path necessary.
That being said, it's still possible to run .py files directly as scripts, provided you've configured the underlying Python environment for them to resolve their dependencies (imports) correctly. To do that, you'll want to define a package structure and "install" the package so that your source code is visible on sys.path.
Here's a minimum example:
my_project
├── another_dir
│ ├── __init__.py <-- __init__ file required for package dirs (it can be empty)
│ └── some_module.py
├── pyproject.toml <-- packaging metadata lives here
└── some_dir <-- no __init__ file necessary for non-packaged subdirs
└── some_script.py
Minimal contents of the packaging definition in pyproject.toml:
[build-system]
requires = ["setuptools"]
build-backend = "setuptools.build_meta"
[project]
name = "my_proj"
version = "0.1"
[tool.setuptools.packages.find]
namespaces = false
An additional once-off step is required to create/configure an environment in between the git clone and the script execution:
python3 -m venv .venv
source .venv/bin/activate
pip install -e .
This makes sure that another_dir is available to import from the environment's site-packages directory, which is already one of the locations on sys.path (check with python -m site). That's what's required for any/all of these import statements to work from within the script file(s)
from another_dir import some_module
import another_dir.some_module
from another_dir.some_module import something
Note that this does not necessarily put the parent of another_dir onto sys.path directly. For an editable install, it will setup some scaffolding which makes your package appear to be "installed" in the site, which is sufficient for those imports to succeed. For a non-editable install (pip install without the -e flag), it will just copy your package directly into the site, compile the .pyc files, and then the code will be found by the normal SourceFileLoader.

mlflow run git-uri clone to specific directory

I am using mlflow run with a GitHub uri.
When I run using the below command
mlflow run <git-uri>
The command sets up a conda environment and then clones the Git repo into a temp directory, But I need it setup in a specific directory
I checked the entire document, but I can't find it. Is there no such option to do so in one shot?
For non-local URIs, MLflow uses the Python's tempfile.mkdtemp function (source code), that creates the temporary directory. You may have some control over it by setting the TMPDIR environment variable as described in Python docs (it lists TMP & TEMP as well, but they didn't work for me on MacOS) - but it will set only "base path" for temporary directories and files, the directory/file names are still will be random.

Build a debian package with user settings

I'm packaging a PyQt application for Linux as a .deb package, following the Debian maintenance guide.
The manual does a good job describing how to build the python binaries with debuild -b, and install global data files in /usr/share/<package>/ through the debian/install file. However, I don't see any mention of installing user settings files - cache files or files for configuration changes that the current user running the program might want to save.
As far as I understand, other programs usually save these in a hidden directory on the users home path - eg atom's user data in /home/<username>/.atom/.
The manual does mention conffiles. However these seem to be globally installed. I'm also not sure if they're suitable for config files that change frequently as a result of user actions, since package updates will attempt to solve conflicts between new and existing conffiles.
Some other documentation mentions postinstall scripts, but this seems potentially too complicated for something that should be common to many debian packages?

Making an Executable out of an entire Python Project

Is there any way I can make an executable out of my Python project? There are many Python scripts that are in my Project and there are SQLite db files as well as other files and folders that are required for the software to run correctly. What is the best way of making this entire project executable?, Should I only make the Python scripts executable?
I have tried Pyinstaller but I am not sure how to bundle all the files into 1 single executable. Shown above is a copy of all the files and folders in my directory.
I think you need to modify the spec file, which PyInstaller creates on a first run. There is a special parameter for data files:
binaries: non-python modules needed by the scripts, including names given by the --add-binary option;
Try adding your database and other data files to this field and they should be included to you package.
For further question I recommend to refer to official documentation and check examples on Github

Packaging Multiple Python Files

I currently am using this guide to package up my project wasp. However currently everything lives inside of the wasp file.
That's not ideal. I would rather have all the classes in separate files so it can be more effectively managed. I have the series of files needed in the debian directory. But I'm not sure how to configure the packaging to package multiple files.
Is there a way to change my packaging to package more than just the one script file?
I'm not a debian package or Python expert, but one way would be to copy the various source files to another location (outside of /usr/bin), and then have /usr/bin/wasp call out to them.
Say you put all of your python code in src/ in the root of your repo. In the debian/install file, you'd have:
wasp usr/bin
src/* usr/lib/wasp/
You'd then just need /usr/bin/wasp to call some entry point in src. For example,
#!/usr/bin/python3
import sys
sys.path.append('/usr/lib/wasp/')
import wasp # or whatever you expose in src
# ...
Again, I don't know the best practices here (either in directory or python usage) but I think this would at least work!

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