Add module docstring for `pathlib._abc`. (#113691)

diff --git a/Lib/pathlib/_abc.py b/Lib/pathlib/_abc.py
index e53921edaa2cae87d55057ed5130db4dff42448b..a6956f251f8b7ea6a92a6e4274079bfacbdd1bb1 100644 (file)
--- a/Lib/pathlib/_abc.py
+++ b/Lib/pathlib/_abc.py
@@ -1,3 +1,16 @@
+"""
+Abstract base classes for rich path objects.
+
+This module is published as a PyPI package called "pathlib-abc".
+
+This module is also a *PRIVATE* part of the Python standard library, where
+it's developed alongside pathlib. If it finds success and maturity as a PyPI
+package, it could become a public part of the standard library.
+
+Two base classes are defined here -- PurePathBase and PathBase -- that
+resemble pathlib's PurePath and Path respectively.
+"""
+
 import functools
 import posixpath
 from errno import ENOENT, ENOTDIR, EBADF, ELOOP, EINVAL