Hi! 👋 Is there way to specify interpreter constraints when

./pants generate-lockfiles

for specific requirements.txt? need some guidance on how to setup codebases requiring multiple python versions. We have 2 big codebases. 1.

py3.7

used in airflow, another

py3.10

used in dockerized apps. To support these, I went with 2 requirements.txt.

3rdparty/airflow/requirements.txt

and

3rdparty/python/requirements.txt

. Added

python_sources(resolve="airflow-default", interpreter_constraints=["CPython>=3.7.10, <3.8"],)

to all BUILD files for airflow codebases. Also changed my

pants.toml

to this:

[python]
interpreter_constraints = ["CPython>=3.7.10, <3.8", "==3.10.*"]

My local python is version

3.10.8

The issue is

./pants generate-lockfiles

when resolving packages for airflow seems to be looking for packages which support 3.10.8. Which causes resolution issues.

I think you want the resolves_to_interpreter_constraints option

Hey. thanks for following up. It did work for 3.10.8 stuff. Have to test airflow, will update once i go through it I completely missed the python section of the doc. Has some interesting options I may need in future. What does the pants community think of having this be documented in https://www.pantsbuild.org/docs/python-interpreter-compatibility? It is critical to for mixed interpreters to work.

We'll happily accept suggestions for documentation improvements! The docs have a "Suggest Edits" button you can use. Thanks!

Will do 🙂 Btw, it didn’t work. Got this error when running py3.7 code:

InvalidFieldException: The target airflow/src/python/tunein/dags/hellodag.py has the `interpreter_constraints` ('CPython>=3.7.10, <3.8',), which are not a subset of the `interpreter_constraints` of some of its dependencies:

  * ('==3.10.*',): airflow/src/python/tunein/__init__.py

To fix this, you should likely adjust airflow/src/python/tunein/dags/hellodag.py's `interpreter_constraints` to match the narrowest range in the above list.

However, I had to make set. interpreter_constraints to ==3.10.* else

./pants test ::

fails:

ib/test/python/tunein/lib/samplelib_test.py:1: in <module>
    from tunein.lib.samplelib import func1, use_requests
E     File "lib/src/python/tunein/lib/samplelib.py", line 17
E       match point:
E                 ^
E   SyntaxError: invalid syntax

It looks like the answer to this is explicitly setting

interpreter_constraints=["==3.10.*"]

in every build file. Is there a better way to do this?