fix: use the python micro version to parse whl metadata in bzlmod

Add `<micro>` version to the target platform. Instead of `cpxy_os_cpu`
the target platform string format becomes `cpxy.z_os_cpu` and this PR
just spikes the implementation to see the main points that need to be
done:
- [ ] test `select_whls` function needs to be tested to ensure that the
  whl selection is not impacted when we have the full version in the
  target platform.
- [ ] `download_only` legacy whl code path in `bzlmod` needs further
  testing.
- [ ] test `whl_config_setting` handling.
- [ ] doc the new format and add changelog.
- [x] `pep508_deps` tests for handling the `full_python_version`
  correctly.

Fixes #2319

Author: aignas

python/private/pypi/extension.bzl

@@ -16,8 +16,10 @@
 
 load("@bazel_features//:features.bzl", "bazel_features")
 load("@pythons_hub//:interpreters.bzl", "INTERPRETER_LABELS")
+load("@pythons_hub//:versions.bzl", "MINOR_MAPPING")
 load("//python/private:auth.bzl", "AUTH_ATTRS")
 load("//python/private:normalize_name.bzl", "normalize_name")
+load("//python/private:full_version.bzl", "full_version")
 load("//python/private:repo_utils.bzl", "repo_utils")
 load("//python/private:semver.bzl", "semver")
 load("//python/private:version_label.bzl", "version_label")
@@ -68,6 +70,7 @@ def _create_whl_repos(
         pip_attr,
         whl_overrides,
         available_interpreters = INTERPRETER_LABELS,
+        minor_mapping = MINOR_MAPPING,
         get_index_urls = None):
     """create all of the whl repositories
 
@@ -159,8 +162,10 @@ def _create_whl_repos(
             requirements_osx = pip_attr.requirements_darwin,
             requirements_windows = pip_attr.requirements_windows,
             extra_pip_args = pip_attr.extra_pip_args,
-            # TODO @aignas 2025-04-15: pass the full version into here
-            python_version = major_minor,
+            python_version = full_version(
+                version=pip_attr.python_version,
+                minor_mapping=minor_mapping,
+            ),
             logger = logger,
         ),
         extra_pip_args = pip_attr.extra_pip_args,
@@ -304,9 +309,6 @@ def _whl_repos(*, requirement, whl_library_args, download_only, netrc, auth_patt
     if requirement.extra_pip_args:
         args["extra_pip_args"] = requirement.extra_pip_args
 
-    if download_only:
-        args.setdefault("experimental_target_platforms", requirement.target_platforms)
-
     target_platforms = requirement.target_platforms if multiple_requirements_for_whl else []
     repo_name = pypi_repo_name(
         normalize_name(requirement.distribution),

python/private/pypi/pkg_aliases.bzl

@@ -370,6 +370,8 @@ def get_filename_config_settings(
             py = "py3_"
 
         abi = parsed.abi_tag
+        # TODO @aignas 2025-04-20: test
+        abi, _, _ = abi.partition(".")
 
         if parsed.platform_tag == "any":
             prefixes = ["{}{}_any".format(py, abi)]

python/private/pypi/requirements_files_by_platform.bzl

@@ -91,13 +91,12 @@ def _platforms_from_args(extra_pip_args):
     return list(platforms.keys())
 
 def _platform(platform_string, python_version = None):
-    if not python_version or platform_string.startswith("cp3"):
+    if not python_version or platform_string.startswith("cp"):
         return platform_string
 
-    _, _, tail = python_version.partition(".")
-    minor, _, _ = tail.partition(".")
+    major, _, tail = python_version.partition(".")
 
-    return "cp3{}_{}".format(minor, platform_string)
+    return "cp{}{}_{}".format(major, tail, platform_string)
 
 def requirements_files_by_platform(
         *,

python/private/pypi/whl_config_setting.bzl

@@ -35,10 +35,20 @@ def whl_config_setting(*, version = None, config_setting = None, filename = None
         a struct with the validated and parsed values.
     """
     if target_platforms:
-        for p in target_platforms:
+        target_platforms_input = target_platforms
+        target_platforms = []
+        for p in target_platforms_input:
             if not p.startswith("cp"):
                 fail("target_platform should start with 'cp' denoting the python version, got: " + p)
 
+            abi, _, tail = p.partition("_")
+            # drop the micro version here, currently there is no usecase to use
+            # multiple python interpreters with the same minor version but
+            # different micro version.
+            abi, _, _ = abi.partition(".")
+            target_platforms.append("{}_{}".format(abi, tail))
+
+
     return struct(
         config_setting = config_setting,
         filename = filename,

python/private/pypi/whl_target_platforms.bzl

@@ -75,8 +75,10 @@ def select_whls(*, whls, want_platforms = [], logger = None):
             fail("expected all platforms to start with ABI, but got: {}".format(p))
 
         abi, _, os_cpu = p.partition("_")
+        abi, _, _ = abi.partition(".")
         _want_platforms[os_cpu] = None
-        _want_platforms[p] = None
+        # TODO @aignas 2025-04-20: add a test
+        _want_platforms["{}_{}".format(abi, os_cpu)] = None
 
         version_limit_candidate = int(abi[3:])
         if not version_limit:

tests/pypi/extension/extension_tests.bzl

@@ -157,6 +157,7 @@ def _test_simple(env):
         available_interpreters = {
             "python_3_15_host": "unit_test_interpreter_target",
         },
+        minor_mapping = {"3.15": "3.15.19"},
     )
 
     pypi.exposed_packages().contains_exactly({"pypi": ["simple"]})
@@ -204,6 +205,7 @@ def _test_simple_multiple_requirements(env):
         available_interpreters = {
             "python_3_15_host": "unit_test_interpreter_target",
         },
+        minor_mapping = {"3.15": "3.15.19"},
     )
 
     pypi.exposed_packages().contains_exactly({"pypi": ["simple"]})
@@ -270,6 +272,7 @@ torch==2.4.1 ; platform_machine != 'x86_64' \
         available_interpreters = {
             "python_3_15_host": "unit_test_interpreter_target",
         },
+        minor_mapping = {"3.15": "3.15.19"},
     )
 
     pypi.exposed_packages().contains_exactly({"pypi": ["torch"]})
@@ -392,6 +395,7 @@ torch==2.4.1+cpu ; platform_machine == 'x86_64' \
         available_interpreters = {
             "python_3_12_host": "unit_test_interpreter_target",
         },
+        minor_mapping = {"3.12": "3.12.19"},
         simpleapi_download = mocksimpleapi_download,
     )
 
@@ -515,6 +519,7 @@ simple==0.0.3 \
         available_interpreters = {
             "python_3_15_host": "unit_test_interpreter_target",
         },
+        minor_mapping = {"3.15": "3.15.19"},
     )
 
     pypi.exposed_packages().contains_exactly({"pypi": ["simple"]})
@@ -544,23 +549,22 @@ simple==0.0.3 \
         "pypi_315_extra": {
             "dep_template": "@pypi//{name}:{target}",
             "download_only": True,
-            "experimental_target_platforms": ["cp315_linux_x86_64"],
+            # TODO @aignas 2025-04-20: ensure that this is in the hub repo
+            # "experimental_target_platforms": ["cp315_linux_x86_64"],
             "extra_pip_args": ["--platform=manylinux_2_17_x86_64", "--python-version=315", "--implementation=cp", "--abi=cp315"],
             "python_interpreter_target": "unit_test_interpreter_target",
             "requirement": "extra==0.0.1 --hash=sha256:deadb00f",
         },
         "pypi_315_simple_linux_x86_64": {
             "dep_template": "@pypi//{name}:{target}",
             "download_only": True,
-            "experimental_target_platforms": ["cp315_linux_x86_64"],
             "extra_pip_args": ["--platform=manylinux_2_17_x86_64", "--python-version=315", "--implementation=cp", "--abi=cp315"],
             "python_interpreter_target": "unit_test_interpreter_target",
             "requirement": "simple==0.0.1 --hash=sha256:deadbeef",
         },
         "pypi_315_simple_osx_aarch64": {
             "dep_template": "@pypi//{name}:{target}",
             "download_only": True,
-            "experimental_target_platforms": ["cp315_osx_aarch64"],
             "extra_pip_args": ["--platform=macosx_10_9_arm64", "--python-version=315", "--implementation=cp", "--abi=cp315"],
             "python_interpreter_target": "unit_test_interpreter_target",
             "requirement": "simple==0.0.3 --hash=sha256:deadbaaf",
@@ -648,6 +652,7 @@ git_dep @ git+https://git.server/repo/project@deadbeefdeadbeef
         available_interpreters = {
             "python_3_15_host": "unit_test_interpreter_target",
         },
+        minor_mapping = {"3.15": "3.15.19"},
         simpleapi_download = mocksimpleapi_download,
     )
 
@@ -850,6 +855,7 @@ optimum[onnxruntime-gpu]==1.17.1 ; sys_platform == 'linux'
         available_interpreters = {
             "python_3_15_host": "unit_test_interpreter_target",
         },
+        minor_mapping = {"3.15": "3.15.19"},
     )
 
     pypi.exposed_packages().contains_exactly({"pypi": []})

tests/pypi/pep508/deps_tests.bzl

@@ -154,7 +154,7 @@ _tests.append(test_self_dependencies_can_come_in_any_order)
 def _test_can_get_deps_based_on_specific_python_version(env):
     requires_dist = [
         "bar",
-        "baz; python_version < '3.8'",
+        "baz; python_full_version < '3.7.3'",
         "posix_dep; os_name=='posix' and python_version >= '3.8'",
     ]
 
@@ -163,6 +163,11 @@ def _test_can_get_deps_based_on_specific_python_version(env):
         requires_dist = requires_dist,
         platforms = ["cp38_linux_x86_64"],
     )
+    py373 = deps(
+        "foo",
+        requires_dist = requires_dist,
+        platforms = ["cp37.3_linux_x86_64"],
+    )
     py37 = deps(
         "foo",
         requires_dist = requires_dist,
@@ -174,6 +179,8 @@ def _test_can_get_deps_based_on_specific_python_version(env):
     env.expect.that_dict(py37.deps_select).contains_exactly({})
     env.expect.that_collection(py38.deps).contains_exactly(["bar", "posix_dep"])
     env.expect.that_dict(py38.deps_select).contains_exactly({})
+    env.expect.that_collection(py373.deps).contains_exactly(["bar"])
+    env.expect.that_dict(py373.deps_select).contains_exactly({})
 
 _tests.append(_test_can_get_deps_based_on_specific_python_version)