It appears that

./pants dependencies --filter-target-type=<target_type> <some_target>

applies the filter to

some_target

, not the list of dependencies, which I find very unintuitive. For example, in directory

db/sample_project_1

I have a

BUILD

that looks like this:

python_sources(
    name="lib",
    sources=["*.py"],
    dependencies=["3rdparty:dbr-9.1-reqs", "db/shared:lib"],
    resolve="databricks",
    tags=["model"]
)

When I call

./pants dependencies db/sample_project_1/__init__.py:lib

I get the following:

3rdparty/requirements-dbr-9.1.txt:dbr-9.1-reqs
3rdparty:dbr-9.1-reqs#boto3
3rdparty:dbr-9.1-reqs#pandas
3rdparty:dbr-9.1-reqs#scikit-learn
3rdparty:dbr-9.1-reqs#scipy
db/shared/__init__.py:lib
db/shared/config.py:lib
db/shared/runner.py:lib
db/shared:reqs#request
db/notebook_utils/__init__.py:lib

which is what I expect. If I do

./pants dependencies db/sample_project_1/__init__.py:lib --filter-target-type="python_source"

, then I get the exact same output. If I do

./pants dependencies db/sample_project_1/__init__.py:lib --filter-target-type="python_requirement"

, then I get nothing. It appears that this is because

db/sample_project_1/__init__.py:lib

itself is a

python_source

I can see how this behavior might be expected if the goal is to filter targets from a glob (e.g. only get dependencies for

python_source

in

::

), but it seems rather unintuitive to me. The question I want to answer here is: “which of this files dependencies are 3rd party requirements vs other sources” and it looks like the best way to do that is something like:

./pants list --filter-target-type=python_requirement $(./pants dependencies db/sample_project_1/__init__.py:lib | tr '\n' ' ')

On a related note, it would be really nice if it was possible to use

--output-file

in append-mode.

To get the side note out of the way, can you open a ticket for an append mode for

--output-file

?

I tried that as well, and it’s super slow since it has to spawn many pants processes. This one from my post is much faster since it only spawns one additional process:

./pants list --filter-target-type=python_requirement $(./pants dependencies db/sample_project_1/__init__.py:lib | tr '\n' ' ')

Is there a reason xargs is preferred?

It should only need to spawn one pants process

Ah yes, I had

xargs -I {} ./pants -lerror list --filter-target-type=python_requirement {}

which would definitely do it