python-3.6.zip added from Github

README.cosmo contains the necessary links.

third_party/python/Mac/BuildScript/scripts/postflight.ensurepip

@@ -0,0 +1,74 @@
+#!/bin/sh
+#
+# Install/upgrade pip.
+#
+
+PYVER="@PYVER@"
+PYMAJOR="@PYMAJOR@"
+FWK="/Library/Frameworks/Python.framework/Versions/${PYVER}"
+RELFWKBIN="../../..${FWK}/bin"
+
+umask 022
+
+"${FWK}/bin/python${PYVER}" -E -s -m ensurepip --upgrade
+
+# bpo-33290: An earlier "pip3 install --upgrade pip" may have installed
+#     a "pip" in the fw bin directory.  For a py3 install, remove it.
+
+rm -f "${FWK}/bin/pip"
+
+"${FWK}/bin/python${PYVER}" -E -s -Wi \
+    "${FWK}/lib/python${PYVER}/compileall.py" -q -j0 \
+    -f -x badsyntax \
+    "${FWK}/lib/python${PYVER}/site-packages"
+
+"${FWK}/bin/python${PYVER}" -E -s -Wi -O \
+    "${FWK}/lib/python${PYVER}/compileall.py" -q -j0 \
+    -f -x badsyntax \
+    "${FWK}/lib/python${PYVER}/site-packages"
+
+chgrp -R admin "${FWK}/lib/python${PYVER}/site-packages" "${FWK}/bin"
+chmod -R g+w "${FWK}/lib/python${PYVER}/site-packages" "${FWK}/bin"
+
+# We do not know if the user selected the Python command-line tools
+# package that installs symlinks to /usr/local/bin.  So we assume
+# that the command-line tools package has already completed or was
+# not selected and we will only install /usr/local/bin symlinks for
+# pip et al if there are /usr/local/bin/python* symlinks to our
+# framework bin directory.
+
+if [ -d /usr/local/bin ] ; then
+    (
+        install_links_if_our_fw() {
+            if [ "$(readlink -n ./$1)" = "${RELFWKBIN}/$1" ] ; then
+                shift
+                for fn ;
+                do
+                    if [ -e "${RELFWKBIN}/${fn}" ] ; then
+                        rm -f ./${fn}
+                        ln -s "${RELFWKBIN}/${fn}" "./${fn}"
+                        chgrp -h admin "./${fn}"
+                        chmod -h g+w "./${fn}"
+                    fi
+                done
+            fi
+        }
+
+        cd /usr/local/bin
+
+        # Create pipx.y and easy_install-x.y links if /usr/local/bin/pythonx.y
+        #   is linked to this framework version
+        install_links_if_our_fw "python${PYVER}" \
+                                    "pip${PYVER}" "easy_install-${PYVER}"
+
+        # Create pipx link if /usr/local/bin/pythonx is linked to this version
+        install_links_if_our_fw "python${PYMAJOR}" \
+                                    "pip${PYMAJOR}"
+
+        # Create pip and easy_install link if /usr/local/bin/python
+        #   is linked to this version
+        install_links_if_our_fw "python" \
+                                    "pip" "easy_install"
+    )
+fi
+exit 0