diff --git a/scripts/Android.bp b/scripts/Android.bp
index 1f55030..ac2f42f 100644
--- a/scripts/Android.bp
+++ b/scripts/Android.bp
@@ -150,6 +150,46 @@
 }
 
 python_binary_host {
+    name: "construct_context",
+    main: "construct_context.py",
+    srcs: [
+        "construct_context.py",
+    ],
+    version: {
+        py2: {
+            enabled: true,
+        },
+        py3: {
+            enabled: false,
+        },
+    },
+    libs: [
+        "manifest_utils",
+    ],
+}
+
+python_test_host {
+    name: "construct_context_test",
+    main: "construct_context_test.py",
+    srcs: [
+        "construct_context_test.py",
+        "construct_context.py",
+    ],
+    version: {
+        py2: {
+            enabled: true,
+        },
+        py3: {
+            enabled: false,
+        },
+    },
+    libs: [
+        "manifest_utils",
+    ],
+    test_suites: ["general-tests"],
+}
+
+python_binary_host {
     name: "lint-project-xml",
     main: "lint-project-xml.py",
     srcs: ["lint-project-xml.py"],
diff --git a/scripts/OWNERS b/scripts/OWNERS
index 0274554..8c64424 100644
--- a/scripts/OWNERS
+++ b/scripts/OWNERS
@@ -1,4 +1,4 @@
 per-file system-clang-format,system-clang-format-2 = enh@google.com,smoreland@google.com
 per-file build-mainline-modules.sh = ngeoffray@google.com,paulduffin@google.com,mast@google.com
 per-file build-aml-prebuilts.sh = ngeoffray@google.com,paulduffin@google.com,mast@google.com
-per-file construct_context.sh = ngeoffray@google.com,calin@google.com,mathieuc@google.com,skvadrik@google.com
+per-file construct_context.py = ngeoffray@google.com,calin@google.com,mathieuc@google.com,skvadrik@google.com
diff --git a/scripts/construct_context.py b/scripts/construct_context.py
new file mode 100755
index 0000000..8717fe3
--- /dev/null
+++ b/scripts/construct_context.py
@@ -0,0 +1,90 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2020 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+"""A tool for constructing class loader context."""
+
+from __future__ import print_function
+
+import argparse
+import sys
+
+from manifest import compare_version_gt
+
+
+def parse_args(args):
+  """Parse commandline arguments."""
+  parser = argparse.ArgumentParser()
+  parser.add_argument('--target-sdk-version', default='', dest='sdk',
+    help='specify target SDK version (as it appears in the manifest)')
+  parser.add_argument('--host-classpath-for-sdk', dest='host_classpaths',
+    action='append', nargs=2, metavar=('sdk','classpath'),
+    help='specify classpath on host for a given SDK version or "any" version')
+  parser.add_argument('--target-classpath-for-sdk', dest='target_classpaths',
+    action='append', nargs=2, metavar=('sdk','classpath'),
+    help='specify classpath on target for a given SDK version or "any" version')
+  return parser.parse_args(args)
+
+# The hidl.manager shared library has a dependency on hidl.base. We manually
+# add that information to the class loader context if we see those libraries.
+HIDL_MANAGER = 'android.hidl.manager-V1.0-java'
+HIDL_BASE    = 'android.hidl.base-V1.0-java'
+
+# Special keyword that means that the classpath should be added to class loader
+# context regardless of the target SDK version.
+any_sdk = 'any'
+
+# We assume that the order of classpath arguments passed to this script is
+# correct (matches the order computed by package manager). It is possible to
+# sort them here, but Soong needs to use deterministic order anyway, so it can
+# as well use the correct order.
+def construct_context(versioned_classpaths, target_sdk):
+  context = []
+  for [sdk, classpath] in versioned_classpaths:
+    if sdk == any_sdk or compare_version_gt(sdk, target_sdk):
+      for jar in classpath.split(':'):
+        pcl = 'PCL[%s]' % jar
+        if HIDL_MANAGER in jar:
+          pcl += '{PCL[%s]}' % jar.replace(HIDL_MANAGER, HIDL_BASE, 1)
+        context.append(pcl)
+  return context
+
+def construct_contexts(args):
+  host_context = construct_context(args.host_classpaths, args.sdk)
+  target_context = construct_context(args.target_classpaths, args.sdk)
+  context_sep = '#'
+  return ('class_loader_context_arg=--class-loader-context=PCL[]{%s} ; ' % context_sep.join(host_context) +
+    'stored_class_loader_context_arg=--stored-class-loader-context=PCL[]{%s}' % context_sep.join(target_context))
+
+def main():
+  """Program entry point."""
+  try:
+    args = parse_args(sys.argv[1:])
+    if not args.sdk:
+      raise SystemExit('target sdk version is not set')
+    if not args.host_classpaths:
+      raise SystemExit('host classpath is not set')
+    if not args.target_classpaths:
+      raise SystemExit('target classpath is not set')
+
+    print(construct_contexts(args))
+
+  # pylint: disable=broad-except
+  except Exception as err:
+    print('error: ' + str(err), file=sys.stderr)
+    sys.exit(-1)
+
+if __name__ == '__main__':
+  main()
diff --git a/scripts/construct_context.sh b/scripts/construct_context.sh
deleted file mode 100755
index d620d08..0000000
--- a/scripts/construct_context.sh
+++ /dev/null
@@ -1,78 +0,0 @@
-#!/bin/bash
-#
-# Copyright (C) 2018 The Android Open Source Project
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-set -e
-
-# target_sdk_version: parsed from manifest
-#
-# outputs
-# class_loader_context_arg: final class loader conext arg
-# stored_class_loader_context_arg: final stored class loader context arg
-
-if [ -z "${target_sdk_version}" ]; then
-    echo "ERROR: target_sdk_version not set"
-    exit 2
-fi
-
-# The hidl.manager shared library has a dependency on hidl.base. We'll manually
-# add that information to the class loader context if we see those libraries.
-hidl_manager="android.hidl.manager-V1.0-java"
-hidl_base="android.hidl.base-V1.0-java"
-
-function add_to_contexts {
-  for i in $1; do
-    if [[ -z "${class_loader_context}" ]]; then
-      export class_loader_context="PCL[$i]"
-    else
-      export class_loader_context+="#PCL[$i]"
-    fi
-    if [[ $i == *"$hidl_manager"* ]]; then
-      export class_loader_context+="{PCL[${i/$hidl_manager/$hidl_base}]}"
-    fi
-  done
-
-  for i in $2; do
-    if [[ -z "${stored_class_loader_context}" ]]; then
-      export stored_class_loader_context="PCL[$i]"
-    else
-      export stored_class_loader_context+="#PCL[$i]"
-    fi
-    if [[ $i == *"$hidl_manager"* ]]; then
-      export stored_class_loader_context+="{PCL[${i/$hidl_manager/$hidl_base}]}"
-    fi
-  done
-}
-
-# The order below must match what the package manager also computes for
-# class loader context.
-
-if [[ "${target_sdk_version}" -lt "28" ]]; then
-  add_to_contexts "${conditional_host_libs_28}" "${conditional_target_libs_28}"
-fi
-
-if [[ "${target_sdk_version}" -lt "29" ]]; then
-  add_to_contexts "${conditional_host_libs_29}" "${conditional_target_libs_29}"
-fi
-
-if [[ "${target_sdk_version}" -lt "30" ]]; then
-  add_to_contexts "${conditional_host_libs_30}" "${conditional_target_libs_30}"
-fi
-
-add_to_contexts "${dex_preopt_host_libraries}" "${dex_preopt_target_libraries}"
-
-# Generate the actual context string.
-export class_loader_context_arg="--class-loader-context=PCL[]{${class_loader_context}}"
-export stored_class_loader_context_arg="--stored-class-loader-context=PCL[]{${stored_class_loader_context}}"
diff --git a/scripts/construct_context_test.py b/scripts/construct_context_test.py
new file mode 100755
index 0000000..0b0b0a3
--- /dev/null
+++ b/scripts/construct_context_test.py
@@ -0,0 +1,81 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2020 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+"""Unit tests for construct_context.py."""
+
+import sys
+import unittest
+
+import construct_context as cc
+
+sys.dont_write_bytecode = True
+
+def construct_contexts(arglist):
+  args = cc.parse_args(arglist)
+  return cc.construct_contexts(args)
+
+classpaths = [
+  '--host-classpath-for-sdk', '28', 'out/zdir/z.jar',
+  '--target-classpath-for-sdk', '28', '/system/z.jar',
+  '--host-classpath-for-sdk', '29', 'out/xdir/x.jar:out/ydir/y.jar',
+  '--target-classpath-for-sdk', '29', '/system/x.jar:/product/y.jar',
+  '--host-classpath-for-sdk', 'any', 'out/adir/a.jar:out/android.hidl.manager-V1.0-java.jar:out/bdir/b.jar',
+  '--target-classpath-for-sdk', 'any', '/system/a.jar:/system/android.hidl.manager-V1.0-java.jar:/product/b.jar',
+]
+
+class ConstructContextTest(unittest.TestCase):
+  def test_construct_context_28(self):
+    args = ['--target-sdk-version', '28'] + classpaths
+    result = construct_contexts(args)
+    expect = ('class_loader_context_arg=--class-loader-context=PCL[]{PCL[out/xdir/x.jar]'
+      '#PCL[out/ydir/y.jar]'
+      '#PCL[out/adir/a.jar]'
+      '#PCL[out/android.hidl.manager-V1.0-java.jar]{PCL[out/android.hidl.base-V1.0-java.jar]}'
+      '#PCL[out/bdir/b.jar]}'
+      ' ; '
+      'stored_class_loader_context_arg=--stored-class-loader-context=PCL[]{PCL[/system/x.jar]'
+      '#PCL[/product/y.jar]'
+      '#PCL[/system/a.jar]'
+      '#PCL[/system/android.hidl.manager-V1.0-java.jar]{PCL[/system/android.hidl.base-V1.0-java.jar]}'
+      '#PCL[/product/b.jar]}')
+    self.assertEqual(result, expect)
+
+  def test_construct_context_29(self):
+    args = ['--target-sdk-version', '29'] + classpaths
+    result = construct_contexts(args)
+    expect = ('class_loader_context_arg=--class-loader-context=PCL[]{PCL[out/adir/a.jar]'
+      '#PCL[out/android.hidl.manager-V1.0-java.jar]{PCL[out/android.hidl.base-V1.0-java.jar]}'
+      '#PCL[out/bdir/b.jar]}'
+      ' ; '
+      'stored_class_loader_context_arg=--stored-class-loader-context=PCL[]{PCL[/system/a.jar]'
+      '#PCL[/system/android.hidl.manager-V1.0-java.jar]{PCL[/system/android.hidl.base-V1.0-java.jar]}'
+      '#PCL[/product/b.jar]}')
+    self.assertEqual(result, expect)
+
+  def test_construct_context_S(self):
+    args = ['--target-sdk-version', 'S'] + classpaths
+    result = construct_contexts(args)
+    expect = ('class_loader_context_arg=--class-loader-context=PCL[]{PCL[out/adir/a.jar]'
+      '#PCL[out/android.hidl.manager-V1.0-java.jar]{PCL[out/android.hidl.base-V1.0-java.jar]}'
+      '#PCL[out/bdir/b.jar]}'
+      ' ; '
+      'stored_class_loader_context_arg=--stored-class-loader-context=PCL[]{PCL[/system/a.jar]'
+      '#PCL[/system/android.hidl.manager-V1.0-java.jar]{PCL[/system/android.hidl.base-V1.0-java.jar]}'
+      '#PCL[/product/b.jar]}')
+    self.assertEqual(result, expect)
+
+if __name__ == '__main__':
+  unittest.main(verbosity=2)