Issue #19551: PEP 453 - OS X installer now installs or upgrades pip by default.
diff --git a/Mac/BuildScript/scripts/postflight.ensurepip b/Mac/BuildScript/scripts/postflight.ensurepip
new file mode 100755
index 0000000..3b97c47
--- /dev/null
+++ b/Mac/BuildScript/scripts/postflight.ensurepip
@@ -0,0 +1,65 @@
+#!/bin/sh
+#
+# Install/upgrade pip.
+#
+
+PYVER="@PYVER@"
+PYMAJOR="3"
+FWK="/Library/Frameworks/Python.framework/Versions/${PYVER}"
+RELFWKBIN="../../..${FWK}/bin"
+
+umask 022
+
+"${FWK}/bin/python${PYVER}" -m ensurepip --upgrade
+
+"${FWK}/bin/python${PYVER}" -Wi \
+ "${FWK}/lib/python${PYVER}/compileall.py" \
+ -f -x badsyntax \
+ "${FWK}/lib/python${PYVER}/site-packages"
+
+"${FWK}/bin/python${PYVER}" -Wi -O \
+ "${FWK}/lib/python${PYVER}/compileall.py" \
+ -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
+ (
+ 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
+ if [ "$(readlink -n ./python${PYVER})" = "${RELFWKBIN}/python${PYVER}" ] ; then
+ for fn in "pip${PYVER}" "easy_install-${PYVER}" ;
+ 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
+ # Create pipx link if /usr/local/bin/pythonx is linked to this version
+ if [ "$(readlink -n ./python${PYMAJOR})" = "${RELFWKBIN}/python${PYMAJOR}" ] ; then
+ for fn in "pip${PYMAJOR}" ;
+ do
+ if [ -e "${RELFWKBIN}/${fn}" ] ; then
+ rm -f ./${fn}
+ ln -s "${RELFWKBIN}/${fn}" "./${fn}"
+ chgrp -h admin "./${fn}"
+ chmod -h g+w "./${fn}"
+ fi
+ done
+ fi
+ )
+fi
+exit 0