create emailer version 1

env/Lib/site-packages/pip/_internal/operations/build/metadata.py

@@ -0,0 +1,37 @@
+"""Metadata generation logic for source distributions.
+"""
+
+import os
+
+from pip._internal.utils.subprocess import runner_with_spinner_message
+from pip._internal.utils.temp_dir import TempDirectory
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from pip._internal.build_env import BuildEnvironment
+    from pip._vendor.pep517.wrappers import Pep517HookCaller
+
+
+def generate_metadata(build_env, backend):
+    # type: (BuildEnvironment, Pep517HookCaller) -> str
+    """Generate metadata using mechanisms described in PEP 517.
+
+    Returns the generated metadata directory.
+    """
+    metadata_tmpdir = TempDirectory(
+        kind="modern-metadata", globally_managed=True
+    )
+
+    metadata_dir = metadata_tmpdir.path
+
+    with build_env:
+        # Note that Pep517HookCaller implements a fallback for
+        # prepare_metadata_for_build_wheel, so we don't have to
+        # consider the possibility that this hook doesn't exist.
+        runner = runner_with_spinner_message("Preparing wheel metadata")
+        with backend.subprocess_runner(runner):
+            distinfo_dir = backend.prepare_metadata_for_build_wheel(
+                metadata_dir
+            )
+
+    return os.path.join(metadata_dir, distinfo_dir)