Index: lang/python310/Makefile
===================================================================
--- lang/python310/Makefile
+++ lang/python310/Makefile
@@ -1,5 +1,6 @@
 PORTNAME=	python
 DISTVERSION=	${PYTHON_DISTVERSION}
+PORTREVISION=	1
 CATEGORIES=	lang python
 MASTER_SITES=	PYTHON/ftp/python/${DISTVERSION:C/[a-z].*//}
 PKGNAMESUFFIX=	${PYTHON_SUFFIX}
@@ -15,7 +16,7 @@
 LIB_DEPENDS=	libffi.so:devel/libffi
 
 USES=		compiler:c11 cpe ncurses pathfix pkgconfig readline \
-		shebangfix ssl tar:xz
+		shebangfix ssl tar:xz trigger
 PATHFIX_MAKEFILEIN=	Makefile.pre.in
 USE_LDCONFIG=	yes
 GNU_CONFIGURE=	yes
@@ -24,6 +25,7 @@
 SHEBANG_FILES+=	Lib/test/ziptestdata/exe_with_z64 \
 		Lib/test/ziptestdata/exe_with_zip \
 		Lib/test/ziptestdata/header.sh
+TRIGGERS=	${PYTHON_VERSION}
 
 # Duplicate python.mk variables. TODO: Let lang/python?? ports use python.mk bits.
 PYTHON_VER=		${PYTHON_DISTVERSION:R}
Index: lang/python310/files/python3.10.ucl.in
===================================================================
--- /dev/null
+++ lang/python310/files/python3.10.ucl.in
@@ -0,0 +1,40 @@
+path_glob: "%%PREFIX%%/lib/python3.10/site-packages/*"
+trigger: {
+	type: lua
+	sandbox: false
+	script: <<EOS
+function cleanup(directory)
+  for _,d in ipairs(pkg.readdir(directory)) do
+    local full_path = directory .. "/" .. d
+    local stat = pkg.stat(full_path)
+    if stat["type"] == "dir" then
+      if (d ~= "__pycache__") then
+        cleanup(full_path)
+      else
+        for _,bytecode_file in ipairs(pkg.readdir(full_path)) do
+          local file_origin = string.gsub(bytecode_file, "[.]cpython[-]310[.].*pyc", ".py")
+          if file_origin  then
+            local origin_path = directory .. "/" .. file_origin
+            if (not pkg.stat(origin_path)) then
+              print("  >=> removed stale bytecode " .. bytecode_file)
+              os.remove(full_path .. "/" .. bytecode_file)
+            end
+          end
+        end
+      end
+      local res = pkg.readdir(full_path)
+      if #res == 0 then
+        print("  >=> removed empty directory " .. full_path )
+        os.remove(full_path)
+      end
+    end
+  end
+end
+
+print(">=> Cleaning stale bytecode files...")
+cleanup("%%PREFIX%%/lib/python3.10/site-packages")
+
+print(">=> Byte-compiling Python source files...")
+pkg.exec({"%%PREFIX%%/bin/python3.10", "-m", "compileall", "-o", "0", "-o", "1", "-o", "2", "%%PREFIX%%/lib/python3.10/site-packages"})
+EOS
+}
Index: lang/python311/Makefile
===================================================================
--- lang/python311/Makefile
+++ lang/python311/Makefile
@@ -1,5 +1,6 @@
 PORTNAME=	python
 DISTVERSION=	${PYTHON_DISTVERSION}
+PORTREVISION=	1
 CATEGORIES=	lang python
 MASTER_SITES=	PYTHON/ftp/python/${DISTVERSION:C/[a-z].*//}
 PKGNAMESUFFIX=	${PYTHON_SUFFIX}
@@ -15,7 +16,7 @@
 LIB_DEPENDS=	libffi.so:devel/libffi
 
 USES=		compiler:c11 cpe ncurses pathfix pkgconfig readline \
-		shebangfix ssl tar:xz
+		shebangfix ssl tar:xz trigger
 PATHFIX_MAKEFILEIN=	Makefile.pre.in
 USE_LDCONFIG=	yes
 GNU_CONFIGURE=	yes
@@ -24,6 +25,7 @@
 SHEBANG_FILES+=	Lib/test/ziptestdata/exe_with_z64 \
 		Lib/test/ziptestdata/exe_with_zip \
 		Lib/test/ziptestdata/header.sh
+TRIGGERS=	${PYTHON_VERSION}
 
 # Duplicate python.mk variables. TODO: Let lang/python?? ports use python.mk bits.
 PYTHON_VER=		${PYTHON_DISTVERSION:R}
Index: lang/python311/files/python3.11.ucl.in
===================================================================
--- /dev/null
+++ lang/python311/files/python3.11.ucl.in
@@ -0,0 +1,40 @@
+path_glob: "%%PREFIX%%/lib/python3.11/site-packages/*"
+trigger: {
+	type: lua
+	sandbox: false
+	script: <<EOS
+function cleanup(directory)
+  for _,d in ipairs(pkg.readdir(directory)) do
+    local full_path = directory .. "/" .. d
+    local stat = pkg.stat(full_path)
+    if stat["type"] == "dir" then
+      if (d ~= "__pycache__") then
+        cleanup(full_path)
+      else
+        for _,bytecode_file in ipairs(pkg.readdir(full_path)) do
+          local file_origin = string.gsub(bytecode_file, "[.]cpython[-]311[.].*pyc", ".py")
+          if file_origin  then
+            local origin_path = directory .. "/" .. file_origin
+            if (not pkg.stat(origin_path)) then
+              print("  >=> removed stale bytecode " .. bytecode_file)
+              os.remove(full_path .. "/" .. bytecode_file)
+            end
+          end
+        end
+      end
+      local res = pkg.readdir(full_path)
+      if #res == 0 then
+        print("  >=> removed empty directory " .. full_path )
+        os.remove(full_path)
+      end
+    end
+  end
+end
+
+print(">=> Cleaning stale bytecode files...")
+cleanup("%%PREFIX%%/lib/python3.11/site-packages")
+
+print(">=> Byte-compiling Python source files...")
+pkg.exec({"%%PREFIX%%/bin/python3.11", "-m", "compileall", "-o", "0", "-o", "1", "-o", "2", "%%PREFIX%%/lib/python3.11/site-packages"})
+EOS
+}
Index: lang/python37/Makefile
===================================================================
--- lang/python37/Makefile
+++ lang/python37/Makefile
@@ -1,5 +1,6 @@
 PORTNAME=	python
 DISTVERSION=	${PYTHON_DISTVERSION}
+PORTREVISION=	1
 CATEGORIES=	lang python
 MASTER_SITES=	PYTHON/ftp/python/${DISTVERSION}
 PKGNAMESUFFIX=	${PYTHON_SUFFIX}
@@ -18,12 +19,13 @@
 LIB_DEPENDS=	libffi.so:devel/libffi \
 		libmpdec.so:math/mpdecimal
 
-USES=		cpe ncurses pathfix pkgconfig readline shebangfix ssl tar:xz
+USES=		cpe ncurses pathfix pkgconfig readline shebangfix ssl tar:xz trigger
 PATHFIX_MAKEFILEIN=	Makefile.pre.in
 USE_LDCONFIG=	yes
 GNU_CONFIGURE=	yes
 python_CMD=	${PREFIX}/bin/python${PYTHON_DISTVERSION:R}
 SHEBANG_FILES=	Lib/*.py Lib/*/*.py Lib/*/*/*.py Lib/*/*/*/*.py
+TRIGGERS=	${PYTHON_VERSION}
 
 # Duplicate python.mk variables. TODO: Let lang/python?? ports use python.mk bits.
 PYTHON_VER=		${PYTHON_DISTVERSION:R}
Index: lang/python37/files/python3.7.ucl.in
===================================================================
--- /dev/null
+++ lang/python37/files/python3.7.ucl.in
@@ -0,0 +1,42 @@
+path_glob: "%%PREFIX%%/lib/python3.7/site-packages/*"
+trigger: {
+	type: lua
+	sandbox: false
+	script: <<EOS
+function cleanup(directory)
+  for _,d in ipairs(pkg.readdir(directory)) do
+    local full_path = directory .. "/" .. d
+    local stat = pkg.stat(full_path)
+    if stat["type"] == "dir" then
+      if (d ~= "__pycache__") then
+        cleanup(full_path)
+      else
+        for _,bytecode_file in ipairs(pkg.readdir(full_path)) do
+          local file_origin = string.gsub(bytecode_file, "[.]cpython[-]37[.].*pyc", ".py")
+          if file_origin  then
+            local origin_path = directory .. "/" .. file_origin
+            if (not pkg.stat(origin_path)) then
+              print("  >=> removed stale bytecode " .. bytecode_file)
+              os.remove(full_path .. "/" .. bytecode_file)
+            end
+          end
+        end
+      end
+      local res = pkg.readdir(full_path)
+      if #res == 0 then
+        print("  >=> removed empty directory " .. full_path )
+        os.remove(full_path)
+      end
+    end
+  end
+end
+
+print(">=> Cleaning stale bytecode files...")
+cleanup("%%PREFIX%%/lib/python3.7/site-packages")
+
+print(">=> Byte-compiling Python source files...")
+pkg.exec({"%%PREFIX%%/bin/python3.7", "-m", "compileall", "%%PREFIX%%/lib/python3.7/site-packages"})
+pkg.exec({"%%PREFIX%%/bin/python3.7", "-O", "-m", "compileall", "%%PREFIX%%/lib/python3.7/site-packages"})
+pkg.exec({"%%PREFIX%%/bin/python3.7", "-OO", "-m", "compileall", "%%PREFIX%%/lib/python3.7/site-packages"})
+EOS
+}
Index: lang/python38/Makefile
===================================================================
--- lang/python38/Makefile
+++ lang/python38/Makefile
@@ -1,5 +1,6 @@
 PORTNAME=	python
 DISTVERSION=	${PYTHON_DISTVERSION}
+PORTREVISION=	1
 CATEGORIES=	lang python
 MASTER_SITES=	PYTHON/ftp/python/${DISTVERSION}
 PKGNAMESUFFIX=	${PYTHON_SUFFIX}
@@ -14,7 +15,7 @@
 
 LIB_DEPENDS=	libffi.so:devel/libffi
 
-USES=		cpe ncurses pathfix pkgconfig readline shebangfix ssl tar:xz
+USES=		cpe ncurses pathfix pkgconfig readline shebangfix ssl tar:xz trigger
 PATHFIX_MAKEFILEIN=	Makefile.pre.in
 USE_LDCONFIG=	yes
 GNU_CONFIGURE=	yes
@@ -23,6 +24,7 @@
 SHEBANG_FILES+=	Lib/test/ziptestdata/exe_with_z64 \
 		Lib/test/ziptestdata/exe_with_zip \
 		Lib/test/ziptestdata/header.sh
+TRIGGERS=	${PYTHON_VERSION}
 
 # Duplicate python.mk variables. TODO: Let lang/python?? ports use python.mk bits.
 PYTHON_VER=		${PYTHON_DISTVERSION:R}
Index: lang/python38/files/python3.8.ucl.in
===================================================================
--- /dev/null
+++ lang/python38/files/python3.8.ucl.in
@@ -0,0 +1,42 @@
+path_glob: "%%PREFIX%%/lib/python3.8/site-packages/*"
+trigger: {
+	type: lua
+	sandbox: false
+	script: <<EOS
+function cleanup(directory)
+  for _,d in ipairs(pkg.readdir(directory)) do
+    local full_path = directory .. "/" .. d
+    local stat = pkg.stat(full_path)
+    if stat["type"] == "dir" then
+      if (d ~= "__pycache__") then
+        cleanup(full_path)
+      else
+        for _,bytecode_file in ipairs(pkg.readdir(full_path)) do
+          local file_origin = string.gsub(bytecode_file, "[.]cpython[-]38[.].*pyc", ".py")
+          if file_origin  then
+            local origin_path = directory .. "/" .. file_origin
+            if (not pkg.stat(origin_path)) then
+              print("  >=> removed stale bytecode " .. bytecode_file)
+              os.remove(full_path .. "/" .. bytecode_file)
+            end
+          end
+        end
+      end
+      local res = pkg.readdir(full_path)
+      if #res == 0 then
+        print("  >=> removed empty directory " .. full_path )
+        os.remove(full_path)
+      end
+    end
+  end
+end
+
+print(">=> Cleaning stale bytecode files...")
+cleanup("%%PREFIX%%/lib/python3.8/site-packages")
+
+print(">=> Byte-compiling Python source files...")
+pkg.exec({"%%PREFIX%%/bin/python3.8", "-m", "compileall", "%%PREFIX%%/lib/python3.8/site-packages"})
+pkg.exec({"%%PREFIX%%/bin/python3.8", "-O", "-m", "compileall", "%%PREFIX%%/lib/python3.8/site-packages"})
+pkg.exec({"%%PREFIX%%/bin/python3.8", "-OO", "-m", "compileall", "%%PREFIX%%/lib/python3.8/site-packages"})
+EOS
+}
Index: lang/python39/Makefile
===================================================================
--- lang/python39/Makefile
+++ lang/python39/Makefile
@@ -1,5 +1,6 @@
 PORTNAME=	python
 DISTVERSION=	${PYTHON_DISTVERSION}
+PORTREVISION=	1
 CATEGORIES=	lang python
 MASTER_SITES=	PYTHON/ftp/python/${DISTVERSION}
 PKGNAMESUFFIX=	${PYTHON_SUFFIX}
@@ -15,7 +16,7 @@
 LIB_DEPENDS=	libffi.so:devel/libffi
 
 USES=		compiler:c11 cpe ncurses pathfix pkgconfig readline \
-		shebangfix ssl tar:xz
+		shebangfix ssl tar:xz trigger
 PATHFIX_MAKEFILEIN=	Makefile.pre.in
 USE_LDCONFIG=	yes
 GNU_CONFIGURE=	yes
@@ -24,6 +25,7 @@
 SHEBANG_FILES+=	Lib/test/ziptestdata/exe_with_z64 \
 		Lib/test/ziptestdata/exe_with_zip \
 		Lib/test/ziptestdata/header.sh
+TRIGGERS=	${PYTHON_VERSION}
 
 # Duplicate python.mk variables. TODO: Let lang/python?? ports use python.mk bits.
 PYTHON_VER=		${PYTHON_DISTVERSION:R}
Index: lang/python39/files/python3.9.ucl.in
===================================================================
--- /dev/null
+++ lang/python39/files/python3.9.ucl.in
@@ -0,0 +1,40 @@
+path_glob: "%%PREFIX%%/lib/python3.9/site-packages/*"
+trigger: {
+	type: lua
+	sandbox: false
+	script: <<EOS
+function cleanup(directory)
+  for _,d in ipairs(pkg.readdir(directory)) do
+    local full_path = directory .. "/" .. d
+    local stat = pkg.stat(full_path)
+    if stat["type"] == "dir" then
+      if (d ~= "__pycache__") then
+        cleanup(full_path)
+      else
+        for _,bytecode_file in ipairs(pkg.readdir(full_path)) do
+          local file_origin = string.gsub(bytecode_file, "[.]cpython[-]39[.].*pyc", ".py")
+          if file_origin  then
+            local origin_path = directory .. "/" .. file_origin
+            if (not pkg.stat(origin_path)) then
+              print("  >=> removed stale bytecode " .. bytecode_file)
+              os.remove(full_path .. "/" .. bytecode_file)
+            end
+          end
+        end
+      end
+      local res = pkg.readdir(full_path)
+      if #res == 0 then
+        print("  >=> removed empty directory " .. full_path )
+        os.remove(full_path)
+      end
+    end
+  end
+end
+
+print(">=> Cleaning stale bytecode files...")
+cleanup("%%PREFIX%%/lib/python3.9/site-packages")
+
+print(">=> Byte-compiling Python source files...")
+pkg.exec({"%%PREFIX%%/bin/python3.9", "-m", "compileall", "-o", "0", "-o", "1", "-o", "2", "%%PREFIX%%/lib/python3.9/site-packages"})
+EOS
+}