diff --git a/scripts/xunit/xunit.py b/scripts/xunit/xunit.py
index c636136..540ef56 100644
--- a/scripts/xunit/xunit.py
+++ b/scripts/xunit/xunit.py
@@ -1,91 +1,112 @@
-
-
-# Copyright (c) 2020, ARM Limited.
-#
-#    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.
-
-from __future__ import print_function
+"""Simple xunit results file creator utility."""
+# Copyright (c) 2020-2022, ARM Limited.
+# SPDX-License-Identifier: Apache-2.0
 import xml.etree.ElementTree as ET
+from xml.dom import minidom
 
-class xunit_results():
-    def __init__(self, name='Testsuites'):
-        self.name = name
+
+class xunit_results:
+    """Xunit results writer."""
+
+    def __init__(self):
+        """Initialize results."""
+        self.name = "testsuites"
         self.suites = []
+
     def create_suite(self, name):
+        """Create xunit suite for results."""
         s = xunit_suite(name)
         self.suites.append(s)
         return s
+
     def write_results(self, filename):
+        """Write the results to the appropriate suites."""
         suites = ET.Element(self.name)
         tree = ET.ElementTree(suites)
         for s in self.suites:
-            testsuite = ET.SubElement(suites, 'testsuite', {'name' : s.name, 'errors' : '0'})
+            testsuite = ET.SubElement(
+                suites, "testsuite", {"name": s.name, "errors": "0"}
+            )
             tests = 0
             failures = 0
             skip = 0
             for t in s.tests:
-                test = ET.SubElement(testsuite, 'testcase', {'name' : t.name, 'classname' : t.classname, 'time' : t.time})
+                test = ET.SubElement(
+                    testsuite,
+                    "testcase",
+                    {"name": t.name, "classname": t.classname, "time": t.time},
+                )
                 tests += 1
                 if t.skip:
                     skip += 1
-                    ET.SubElement(test, 'skipped', {'type' : 'Skipped test'})
+                    ET.SubElement(test, "skipped", {"type": "Skipped test"})
                 if t.fail:
                     failures += 1
-                    fail = ET.SubElement(test, 'failure', {'type' : 'Test failed'})
+                    fail = ET.SubElement(test, "failure", {"type": "Test failed"})
                     fail.text = t.fail
                 if t.sysout:
-                    sysout = ET.SubElement(test, 'system-out')
+                    sysout = ET.SubElement(test, "system-out")
                     sysout.text = t.sysout
                 if t.syserr:
-                    syserr = ET.SubElement(test, 'system-err')
+                    syserr = ET.SubElement(test, "system-err")
                     syserr.text = t.syserr
-            testsuite.attrib['tests'] = str(tests)
-            testsuite.attrib['failures'] = str(failures)
-            testsuite.attrib['skip'] = str(skip)
-        tree.write(filename, 'UTF-8', True)
+            testsuite.attrib["tests"] = str(tests)
+            testsuite.attrib["failures"] = str(failures)
+            testsuite.attrib["skip"] = str(skip)
+        xmlstr = minidom.parseString(ET.tostring(tree.getroot())).toprettyxml(
+            indent="  "
+        )
+        with open(filename, "w") as f:
+            f.write(xmlstr)
 
 
-class xunit_suite():
+class xunit_suite:
+    """Xunit suite for test results."""
+
     def __init__(self, name):
+        """Initialize suite."""
         self.name = name
         self.tests = []
 
-class xunit_test():
+
+# classname should be of the form suite.class/subclass/subclass2/...
+# You can have an unlimited number of subclasses in this manner
+
+
+class xunit_test:
+    """Xunit test result."""
+
     def __init__(self, name, classname=None):
+        """Initialize test."""
         self.name = name
         if classname:
             self.classname = classname
         else:
             self.classname = name
-        self.time = '0.000'
+        self.time = "0.000"
         self.fail = None
         self.skip = False
         self.sysout = None
         self.syserr = None
+
     def failed(self, text):
+        """Set test failed information."""
         self.fail = text
+
     def skipped(self):
+        """Set test as skipped."""
         self.skip = True
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
+    # Simple test
     r = xunit_results()
-    s = r.create_suite('selftest')
-    for i in range(0,10):
-        t = xunit_test('atest' + str(i))
+    s = r.create_suite("selftest")
+    for i in range(0, 10):
+        t = xunit_test("atest" + str(i), "selftest")
         if i == 3:
-            t.failed('Unknown failure foo')
+            t.failed("Unknown failure foo")
         if i == 7:
             t.skipped()
         s.tests.append(t)
-    r.write_results('foo.xml')
+    r.write_results("foo.xml")