diff --git a/tools/BUILD.bazel b/tools/BUILD.bazel
index 75b0de6..3170820 100644
--- a/tools/BUILD.bazel
+++ b/tools/BUILD.bazel
@@ -8,7 +8,7 @@
     srcs=["java-event-log-tags.py"],
     deps=[":event_log_tags"],
     visibility = ["//visibility:public"],
-    python_version = "PY2",
+    python_version = "PY3",
 )
 
 py_binary(
@@ -16,5 +16,5 @@
     srcs=["merge-event-log-tags.py"],
     deps=[":event_log_tags"],
     visibility = ["//visibility:public"],
-    python_version = "PY2",
+    python_version = "PY3",
 )
diff --git a/tools/event_log_tags.py b/tools/event_log_tags.py
index 35b2de0..a6ae9f1 100644
--- a/tools/event_log_tags.py
+++ b/tools/event_log_tags.py
@@ -55,12 +55,13 @@
     if file_object is None:
       try:
         file_object = open(filename, "rb")
-      except (IOError, OSError), e:
+      except (IOError, OSError) as e:
         self.AddError(str(e))
         return
 
     try:
       for self.linenum, line in enumerate(file_object):
+        line = line.decode('utf-8')
         self.linenum += 1
         line = re.sub('#.*$', '', line) # strip trailing comments
         line = line.strip()
@@ -100,7 +101,7 @@
 
         self.tags.append(Tag(tag, tagname, description,
                              self.filename, self.linenum))
-    except (IOError, OSError), e:
+    except (IOError, OSError) as e:
       self.AddError(str(e))
 
 
@@ -128,8 +129,8 @@
       output_file = "<stdout>"
     else:
       out = open(output_file, "wb")
-    out.write(data)
+    out.write(str.encode(data))
     out.close()
-  except (IOError, OSError), e:
-    print >> sys.stderr, "failed to write %s: %s" % (output_file, e)
+  except (IOError, OSError) as e:
+    print("failed to write %s: %s" % (output_file, e), file=sys.stderr)
     sys.exit(1)
diff --git a/tools/java-event-log-tags.py b/tools/java-event-log-tags.py
index 37cd712..4bd6d2b 100755
--- a/tools/java-event-log-tags.py
+++ b/tools/java-event-log-tags.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Copyright (C) 2009 The Android Open Source Project
 #
@@ -23,7 +23,7 @@
 -h to display this usage message and exit.
 """
 
-import cStringIO
+from io import StringIO
 import getopt
 import os
 import os.path
@@ -36,24 +36,24 @@
 
 try:
   opts, args = getopt.getopt(sys.argv[1:], "ho:")
-except getopt.GetoptError, err:
-  print str(err)
-  print __doc__
+except getopt.GetoptError as err:
+  print(str(err))
+  print(__doc__)
   sys.exit(2)
 
 for o, a in opts:
   if o == "-h":
-    print __doc__
+    print(__doc__)
     sys.exit(2)
   elif o == "-o":
     output_file = a
   else:
-    print >> sys.stderr, "unhandled option %s" % (o,)
+    print("unhandled option %s" % (o,), file=sys.stderr)
     sys.exit(1)
 
 if len(args) != 1 and len(args) != 2:
-  print "need one or two input files, not %d" % (len(args),)
-  print __doc__
+  print("need one or two input files, not %d" % (len(args),))
+  print(__doc__)
   sys.exit(1)
 
 fn = args[0]
@@ -92,10 +92,10 @@
 
 if tagfile.errors:
   for fn, ln, msg in tagfile.errors:
-    print >> sys.stderr, "%s:%d: error: %s" % (fn, ln, msg)
+    print("%s:%d: error: %s" % (fn, ln, msg), file=sys.stderr)
   sys.exit(1)
 
-buffer = cStringIO.StringIO()
+buffer = StringIO()
 buffer.write("/* This file is auto-generated.  DO NOT MODIFY.\n"
              " * Source file: %s\n"
              " */\n\n" % (fn,))
diff --git a/tools/merge-event-log-tags.py b/tools/merge-event-log-tags.py
index 64bad3f..292604c 100755
--- a/tools/merge-event-log-tags.py
+++ b/tools/merge-event-log-tags.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Copyright (C) 2009 The Android Open Source Project
 #
@@ -24,7 +24,7 @@
 -h to display this usage message and exit.
 """
 
-import cStringIO
+from io import StringIO
 import getopt
 try:
   import hashlib
@@ -48,21 +48,21 @@
 
 try:
   opts, args = getopt.getopt(sys.argv[1:], "ho:m:")
-except getopt.GetoptError, err:
-  print str(err)
-  print __doc__
+except getopt.GetoptError as err:
+  print(str(err))
+  print(__doc__)
   sys.exit(2)
 
 for o, a in opts:
   if o == "-h":
-    print __doc__
+    print(__doc__)
     sys.exit(2)
   elif o == "-o":
     output_file = a
   elif o == "-m":
     pre_merged_file = a
   else:
-    print >> sys.stderr, "unhandled option %s" % (o,)
+    print("unhandled option %s" % (o,), file=sys.stderr)
     sys.exit(1)
 
 # Restrictions on tags:
@@ -133,12 +133,12 @@
 
 if errors:
   for fn, ln, msg in errors:
-    print >> sys.stderr, "%s:%d: error: %s" % (fn, ln, msg)
+    print("%s:%d: error: %s" % (fn, ln, msg), file=sys.stderr)
   sys.exit(1)
 
 if warnings:
   for fn, ln, msg in warnings:
-    print >> sys.stderr, "%s:%d: warning: %s" % (fn, ln, msg)
+    print("%s:%d: warning: %s" % (fn, ln, msg), file=sys.stderr)
 
 # Python's hash function (a) isn't great and (b) varies between
 # versions of python.  Using md5 is overkill here but is the same from
@@ -154,14 +154,14 @@
 # If we were provided pre-merged tags (w/ the -m option), then don't
 # ever try to allocate one, just fail if we don't have a number
 
-for name, t in sorted(by_tagname.iteritems()):
+for name, t in sorted(by_tagname.items()):
   if t.tagnum is None:
     if pre_merged_tags:
       try:
         t.tagnum = pre_merged_tags[t.tagname]
       except KeyError:
-        print >> sys.stderr, ("Error: Tag number not defined for tag `%s'."
-            +" Have you done a full build?") % t.tagname
+        print("Error: Tag number not defined for tag `%s'. Have you done a full build?" % t.tagname,
+              file=sys.stderr)
         sys.exit(1)
     else:
       while True:
@@ -174,8 +174,8 @@
 
 # by_tagnum should be complete now; we've assigned numbers to all tags.
 
-buffer = cStringIO.StringIO()
-for n, t in sorted(by_tagnum.iteritems()):
+buffer = StringIO()
+for n, t in sorted(by_tagnum.items()):
   if t.description:
     buffer.write("%d %s %s\n" % (t.tagnum, t.tagname, t.description))
   else: