mkPythonMetaPackage: init meta package function (and psycopg2-binary) (#337621) (c3925f72) · Commits · nix / nixpkgs

doc/languages-frameworks/python.section.md

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		@@ -361,6 +361,22 @@ modifications.

		Do pay attention to passing in the right Python version!

		#### `mkPythonMetaPackage` function {#mkpythonmetapackage-function}

		This will create a meta package containing [metadata files](https://packaging.python.org/en/latest/specifications/recording-installed-packages/) to satisfy a dependency on a package, without it actually having been installed into the environment.
		In nixpkgs this is used to package Python packages with split binary/source distributions such as [psycopg2](https://pypi.org/project/psycopg2/)/[psycopg2-binary](https://pypi.org/project/psycopg2-binary/).

		```nix
		mkPythonMetaPackage {
		pname = "pscycopg2-binary";
		inherit (psycopg2) optional-dependencies version;
		dependencies = [ psycopg2 ];
		meta = {
		inherit (psycopg2.meta) description homepage;
		};
		}
		```

		#### `python.buildEnv` function {#python.buildenv-function}

		Python environments can be created using the low-level `pkgs.buildEnv` function.

0 → 100644

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		{
		buildPythonPackage,
		lib,
		hatchling,
		}:
		{
		pname,
		version,
		dependencies ? [ ],
		optional-dependencies ? { },
		passthru ? { },
		meta ? { },
		}:

		# Create a "fake" meta package to satisfy a dependency on a package, but don't actually build it.
		# This is useful for packages that have a split binary/source dichotomy like psycopg2/psycopg2-binary,
		# where we want to use the former, but some projects declare a dependency on the latter.

		buildPythonPackage {
		inherit
		pname
		version
		dependencies
		optional-dependencies
		meta
		passthru
		;

		pyproject = true;

		# Make a minimal pyproject.toml that can be built
		unpackPhase = ''
		cat > pyproject.toml << EOF
		[project]
		name = "${pname}"
		version = "${version}"
		dependencies = ${builtins.toJSON (map lib.getName dependencies)}

		[project.optional-dependencies]
		${lib.optionalString (optional-dependencies != { }) (
		(lib.concatStringsSep "\n" (
		lib.mapAttrsToList (
		group: deps: group + " = " + builtins.toJSON (map lib.getName deps)
		) optional-dependencies
		))
		)}

		[tool.hatch.build.targets.wheel]
		bypass-selection = true

		[build-system]
		requires = ["hatchling"]
		build-backend = "hatchling.build"
		EOF
		'';

		build-system = [ hatchling ];
		}

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		@@ -61,6 +61,8 @@ let

		removePythonPrefix = lib.removePrefix namePrefix;

		mkPythonMetaPackage = callPackage ./meta-package.nix { };

		# Convert derivation to a Python module.
		toPythonModule = drv:
		drv.overrideAttrs( oldAttrs: {
		@@ -97,6 +99,7 @@ in {
		inherit buildPythonPackage buildPythonApplication;
		inherit hasPythonModule requiredPythonModules makePythonPath disabled disabledIf;
		inherit toPythonModule toPythonApplication;
		inherit mkPythonMetaPackage;

		python = toPythonModule python;

0 → 100644

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		{
		mkPythonMetaPackage,
		psycopg2,
		}:
		mkPythonMetaPackage {
		pname = "pscycopg2-binary";
		inherit (psycopg2) version;
		dependencies = [ psycopg2 ];
		optional-dependencies = psycopg2.optional-dependencies or { };
		meta = {
		inherit (psycopg2.meta) description homepage;
		};
		}

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		@@ -10952,6 +10952,8 @@ self: super: with self; {

		psycopg2cffi = callPackage ../development/python-modules/psycopg2cffi { };

		psycopg2-binary = callPackage ../development/python-modules/psycopg2-binary { };

		psygnal = callPackage ../development/python-modules/psygnal { };

		ptable = callPackage ../development/python-modules/ptable { };