Convert ParseError instead of createing a new one whole-cloth.

Author: cpyle0819

aws_doc_sdk_examples_tools/doc_gen_test.py

@@ -324,7 +324,4 @@ def test_invalid_xml():
         first_error.value
         == "<fake><para>Certain characters like < are invalid</para></fake>"
     )
-    assert (
-        first_error.message()
-        == "ParseError('not well-formed (invalid token): line 1, column 37')"
-    )
+    assert first_error.message() == "not well-formed (invalid token): line 1, column 37"

aws_doc_sdk_examples_tools/metadata_validator.py

@@ -1,4 +1,3 @@
-#!/usr/bin/env python3
 # Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 # SPDX-License-Identifier: Apache-2.0
 
@@ -174,7 +173,7 @@ def _validate_aws_entity_usage(value: str) -> bool:
         try:
             xtree = xml_tree.fromstring(xml_str)
         except ParseError as e:
-            raise ElementTreeParseError(message=repr(e), raw=xml_str)
+            raise ElementTreeParseError(message=f"{e}", raw=xml_str) from e
         blocks = (
             xtree.findall(".//programlisting")
             + xtree.findall(".//code")