--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/python3.8/site-packages/setuptools/namespaces.py	Mon Jul 27 03:47:31 2020 -0400
@@ -0,0 +1,111 @@
+import os
+from distutils import log
+import itertools
+
+from setuptools.extern.six.moves import map
+
+
+flatten = itertools.chain.from_iterable
+
+
+class Installer:
+
+    nspkg_ext = '-nspkg.pth'
+
+    def install_namespaces(self):
+        nsp = self._get_all_ns_packages()
+        if not nsp:
+            return
+        filename, ext = os.path.splitext(self._get_target())
+        filename += self.nspkg_ext
+        self.outputs.append(filename)
+        log.info("Installing %s", filename)
+        lines = map(self._gen_nspkg_line, nsp)
+
+        if self.dry_run:
+            # always generate the lines, even in dry run
+            list(lines)
+            return
+
+        with open(filename, 'wt') as f:
+            f.writelines(lines)
+
+    def uninstall_namespaces(self):
+        filename, ext = os.path.splitext(self._get_target())
+        filename += self.nspkg_ext
+        if not os.path.exists(filename):
+            return
+        log.info("Removing %s", filename)
+        os.remove(filename)
+
+    def _get_target(self):
+        return self.target
+
+    _nspkg_tmpl = (
+        "import sys, types, os",
+        "has_mfs = sys.version_info > (3, 5)",
+        "p = os.path.join(%(root)s, *%(pth)r)",
+        "importlib = has_mfs and __import__('importlib.util')",
+        "has_mfs and __import__('importlib.machinery')",
+        (
+            "m = has_mfs and "
+            "sys.modules.setdefault(%(pkg)r, "
+            "importlib.util.module_from_spec("
+            "importlib.machinery.PathFinder.find_spec(%(pkg)r, "
+            "[os.path.dirname(p)])))"
+        ),
+        (
+            "m = m or "
+            "sys.modules.setdefault(%(pkg)r, types.ModuleType(%(pkg)r))"
+        ),
+        "mp = (m or []) and m.__dict__.setdefault('__path__',[])",
+        "(p not in mp) and mp.append(p)",
+    )
+    "lines for the namespace installer"
+
+    _nspkg_tmpl_multi = (
+        'm and setattr(sys.modules[%(parent)r], %(child)r, m)',
+    )
+    "additional line(s) when a parent package is indicated"
+
+    def _get_root(self):
+        return "sys._getframe(1).f_locals['sitedir']"
+
+    def _gen_nspkg_line(self, pkg):
+        # ensure pkg is not a unicode string under Python 2.7
+        pkg = str(pkg)
+        pth = tuple(pkg.split('.'))
+        root = self._get_root()
+        tmpl_lines = self._nspkg_tmpl
+        parent, sep, child = pkg.rpartition('.')
+        if parent:
+            tmpl_lines += self._nspkg_tmpl_multi
+        return ';'.join(tmpl_lines) % locals() + '\n'
+
+    def _get_all_ns_packages(self):
+        """Return sorted list of all package namespaces"""
+        pkgs = self.distribution.namespace_packages or []
+        return sorted(flatten(map(self._pkg_names, pkgs)))
+
+    @staticmethod
+    def _pkg_names(pkg):
+        """
+        Given a namespace package, yield the components of that
+        package.
+
+        >>> names = Installer._pkg_names('a.b.c')
+        >>> set(names) == set(['a', 'a.b', 'a.b.c'])
+        True
+        """
+        parts = pkg.split('.')
+        while parts:
+            yield '.'.join(parts)
+            parts.pop()
+
+
+class DevelopInstaller(Installer):
+    def _get_root(self):
+        return repr(str(self.egg_path))
+
+    def _get_target(self):
+        return self.egg_link