Is naming the real confusion or is it existence? I know Pants fairly well and am continually bamboozled by the fact I need to lay down an empty

python_library()

declaration for my

pex_binary(...actual metadata I wrote down...)

to work. Whether the - what looks like a no-op -

python_library()

was a

foo()

or a

bar()

I'd still be mystified by the need. I can go read excellent docs that explain this to me, but at that point the newbie game is up and I can learn what

python_library()

the word means.

Indeed, its existence is the bigger issue. https://pantsbuild.slack.com/archives/C046T6T9U/p1610655122036800?thread_ts=1610638933.024700&cid=C046T6T9U Renaming is meant to make things more clear, but the better solution is to redesign "metadata for first party code" from first principles

OK, great. That's felt like a hard sell in the past but it seems we're all on board with the long term goal.

Pyproject uses the term packages for things to include (modules, packages, directories of python code): https://python-poetry.org/docs/pyproject/ python-packaging (setup.py) uses

install_requires: <https://python-packaging.readthedocs.io/en/latest/dependencies.html|https://python-packaging.readthedocs.io/en/latest/dependencies.html>

setup.py

uses packages to name the code that is around the file and not explicitly named within the file.

The key nuance for me is that targets are broken for first party code. I do think they work well for third party requirements + artifacts you want to build

Well - by definition you need metadata to even name third party code.

I think this shows that there is no community standard that we can lean on that will make pant’s naming 100% understandable without some initiation.

Agreed.

Eric's suggestion is about the only language neutral one I can image (sources). Library seemed similarly language neutral to the inventors but is apparanetly not.

If we continue to have good documentation and good enough names, I think the particular names we choose for targets will not be a big hurdle to the adoption of pants.

+1

I like

python_packages

or

python_requirements

but the latter has a macro namespace collision that makes it not work in pants-land.

True. One concrete thing we can improve is a small "warning" tooltip clarifying this misconception people have with

python_library

. We've had 4 users the past few months be tripped up by this iirc, I do think it's a real problem. But the better solution is to fix targets for first party code, so this rename introduces possibly unnecessary churn.

I think the latter is artificial. If the implementation of

python_requirements

were changed to a target a rule could take empty python_requirements and slurp in a sibling requirementstx, it could take, otherwise, either a file= or *reqs args.

I also like the way pyproject let’s one refine the source of the package/module: via pip, as

sdist

, a module directory, etc. Letting a particular

BUILD

define all its dependencies independent of the monorepo would make refactoring some of our over entangled projects easier to upgrade.

We received a pre release of one of our dependencies from the vendor in a tar.gz file. How can I use this in my project?

Hi Everyone, I am working on a pants 1.9.0 project that uses python 2.7. Upon running any pants comments i get this error

./pants build rapidfire::
/Users/aminghadersohi/.cache/pants/setup/bootstrap-Darwin-x86_64/1.10.0/lib/python2.7/site-packages/OpenSSL/crypto.py:12: CryptographyDeprecationWarning: Python 2 is no longer supported by the Python core team. Support for it is now deprecated in cryptography, and will be removed in a future release.
  from cryptography import x509
timestamp: 2021-01-14T20:56:24.152463
Exception caught: (exceptions.UnicodeDecodeError) (backtrace omitted)
Exception message: 'ascii' codec can't decode byte 0xe2 in position 4: ordinal not in range(128)

i am on mac os catalina, running python 2.7.16

Hi folks

I use

node_module

target to build the frontend application and see that it's built and the build directory is in the

.pants.d

directory, however I would like to embed what's built into a Python application and the produced build is not getting included. I'm new to Pants, I feel like I might be missing something.

python37_binary(
    name = "testing_foo",
    source = "hello_world.py",
    dependencies = [
        ":testing_lib",
    ],
)

python3_library(
    name = "testing_lib",
    sources = [
        "!hello_world.py",
    ],
    dependencies = [
        ":resources",
        "src/frontend"
    ],
)


resources(
    name = "resources",
    sources = [
        "resources/**/*.yml",
        "web/templates/**/*",
    ]
)

This is the build file for the python app. This is the BUILD.py file for react app

node_module(
  name = "frontend",
  sources = [
    "package.json",
    "yarn.lock",
    ".npmrc",
    ".prettierrc",
    ".eslintrc.json",
    "tsconfig.json",
    "public/**/*",
    "src/**/*",
    "scripts/**/*",
    "config/**/*"
  ],
  build_script = "build",
  output_dir = "build",
  package_manager = "yarn",
)

Hey! I'm trying to configure an existing repository with pants V2. One of our dependencies is

h2o_pysparkling_2.4

which needs to be mapped using

module_mapping

. However, the

.

in the package name seems to prevent pants to understand how to do the mapping. Is this intended behaviour? If not, any idea how to get around this?

Hey! I have trouble packaging an executable. Well, actually packaging is successful, but when I try to run it I get:

env: python3.8: No such file or directory

. Probably I’m using the wrong Python distribution or?

This probably means the machine you built the PEX file on has python3.8 but the machine you tried to run it on does not. Does that sound about right?

Assuming I've got this right, there is no easy recommendation here. If the code is compatible with all Python 3's you expect will be installed and available on the machine you deploy to, you might specify a custom shebang as

/usr/bin/env python3

here: https://www.pantsbuild.org/docs/python-target-types#pex_binary

But, that might not be appropriate for your setup either. Would need to know more details of the apps python compatibility and the interpreters installed on your various target machines.

Is it possible to create more than one

resources

using a macro? The thing is... In each package within my monorepo, I'm defining two exactly the same resources, like this:

resources(
    name = "py.typed",
    sources = ["py.typed"],
)

resources(
    name = "VERSION",
    sources = ["VERSION"],
)

It would be nice if I can simplify this to something like this:

my_standard_resources()

I have now installed python3.8 from homebrew and relinked to this version. Now I get a little further. I can:

./pants run apps/app_a

. But when I try to

./pants package apps/a

I get this error:

Exception: String("Can only merge Directories with no duplicates, but found 3 duplicate entries in :\n\n`__init__.py`: 1.) file digest=e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 size=0:\n\n\n\n`__init__.py`: 2.) file digest=c4f92a69e828f5701ffebac2959f704f9fe06ef3d559e146663cb14d44866416 size=1674:\n\n\"\"\"Helper classes for configuration management.\"\"\"\nimport os\n\n\nclass ModelConfig:\n    \"\"\"Model configuration class.\"\"\"\n\n    def __init__(\n        self, name: str, link: str, checksum: str, language_code=\"en\"\n    ):\n        self.fullname = name\n        self.link = link\n        self.language_code = language_code\n        self.checksum = checksum\n\n    def get_fullname(self):\n        \"\"\"\n\n        Returns\n        -------\n        Model fullname, i.e. \'<name_of_model>-<version>\'\n        \"\"\"\n        return self.fullname\n\n    def get_name(self):\n        \"\"\"\n\n        Returns\n        -------\n        model name without version\n\n        \"\"\"\n        return self.fullname.split(\"-\")[0]\n\n    def get_link(self):\n        \"\"\"\n\n        Returns\n        -------\n        model link\n        \"\"\"\n        return self.link\n\n    def get_language_code(self):\n        \"\"\"\n\n        Returns\n        -------\n        model language code\n        \"\"\"\n        return self.language_code\n\n    def get_version(self):\n        \"\"\"\n\n        Returns\n        --\n... TRUNCATED contents from 1674B to 1024B (Pass -ldebug to see full contents).\n\n`__init__.py`: 3.) file digest=e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 size=0:\n\n")

I’ve not been able to understand what I’m doing wrong.

Ok, before addressing the error here, let me back up to our prior exchange. In that exchange I assumed you were building the PEX on one machine and running it on another. That was apparently not the case. You were building and running on the same machine. Is that correct?

... but plowing ahead to the error you just presented - it just means you have a python package under multiple source roots and the package has different

__init__.py

contents in different source roots. That is not good from a Python perspective - nothing to do with Pants. I can explain why its not good if that's not clear - just speak up. To be more concrete though, an example: Say you have these source roots:

a/root1
a/root2
a/root3

Under the first two you have the same Python package `bob`:

a/root1/bob/
  __init__.py
  jake.py
a/root2/bob/
  __init__py
  jane.py

I'm claiming

a/root1/bob/__init__.py

and

a/root2/bob/__init__.py

have different contents and Pants is complaining (rightly) about that.