https://github.com/google/mozc/issues/462

--- /src/base/gen_character_set.py
+++ /src/base/gen_character_set.py
@@ -33,7 +33,6 @@
 import itertools
 import optparse
 import re
-import string
 import sys
 
 
@@ -89,7 +88,8 @@
   @staticmethod
   def _LoadTable(filename, column_index, pattern, validater):
     result = set()
-    for line in open(filename):
+    fh = open(filename)
+    for line in fh:
       if line.startswith('#'):
         # Skip a comment line.
         continue
@@ -100,6 +100,7 @@
         ucs = int(match.group(1), 16)
         if validater(ucs):
           result.add(ucs)
+    fh.close()
 
     return result
 
@@ -250,7 +251,7 @@
   # (at most) four code points.
   bit_list = []
   for _, group in itertools.groupby(enumerate(category_list),
-                                    lambda (codepoint, _): codepoint / 4):
+                                    lambda x: x[0] // 4):
     # Fill bits from LSB to MSB for each group.
     bits = 0
     for index, (_, category) in enumerate(group):
@@ -263,7 +264,7 @@
 
   # Output the content. Each line would have (at most) 16 bytes.
   for _, group in itertools.groupby(enumerate(bit_list),
-                                    lambda (index, _): index / 16):
+                                    lambda x: x[0] // 16):
     line = ['    \"']
     for _, bits in group:
       line.append('\\x%02X' % bits)
@@ -386,7 +387,7 @@
   # Bitmap lookup.
   # TODO(hidehiko): the bitmap has two huge 0-bits ranges. Reduce them.
   category_map = [
-      (bits, category) for category, bits in CATEGORY_BITMAP.iteritems()]
+      (bits, category) for category, bits in CATEGORY_BITMAP.items()]
   category_map.sort()
 
   lines.extend([
@@ -451,7 +452,7 @@
                                      options.jisx0213file)
   category_list = [
       categorizer.GetCategory(codepoint)
-      for codepoint in xrange(categorizer.MaxCodePoint() + 1)]
+      for codepoint in range(categorizer.MaxCodePoint() + 1)]
   generated_character_set_header = GenerateCharacterSetHeader(category_list)
 
   # Write the result.
--- /src/base/gen_config_file_stream_data.py
+++ /src/base/gen_config_file_stream_data.py
@@ -58,7 +58,7 @@
   result = []
   result.append(' { "%s",  "' % os.path.basename(path))
   with open(path, 'rb') as stream:
-    result.extend(r'\x%02X' % ord(byte) for byte in stream.read())
+    result.extend(r'\x%02X' % byte for byte in stream.read())
   result.append('",  %d }' % os.path.getsize(path))
 
   return ''.join(result)
@@ -93,8 +93,8 @@
 def main():
   (options, args) = ParseOptions()
   if not options.output:
-    print >>sys.stderr, (
-        'usage: gen_config_file_stream_data.py --output=filepath input ...')
+    print('usage: gen_config_file_stream_data.py --output=filepath input ...',
+          file=sys.stderr)
     sys.exit(2)
 
   with open(options.output, 'w') as output:
--- /src/build_mozc.py
+++ /src/build_mozc.py
@@ -943,7 +943,7 @@
       logging.info('running %s...', binary)
       try:
         test_function(binary, gtest_report_dir, options)
-      except RunOrDieError, e:
+      except RunOrDieError as e:
         logging.error(e)
         failed_tests.append(binary)
   else:
@@ -1082,7 +1082,7 @@
   # and '-c' and 'Release' are build options.
   targets = []
   build_options = []
-  for i in xrange(len(args)):
+  for i in range(len(args)):
     if args[i].startswith('-'):
       # starting with build options
       build_options = args[i:]
@@ -1190,14 +1190,14 @@
 
 def ShowHelpAndExit():
   """Shows the help message."""
-  print 'Usage: build_mozc.py COMMAND [ARGS]'
-  print 'Commands: '
-  print '  gyp          Generate project files.'
-  print '  build        Build the specified target.'
-  print '  runtests     Build all tests and run them.'
-  print '  clean        Clean all the build files and directories.'
-  print ''
-  print 'See also the comment in the script for typical usage.'
+  print('Usage: build_mozc.py COMMAND [ARGS]')
+  print('Commands: ')
+  print('  gyp          Generate project files.')
+  print('  build        Build the specified target.')
+  print('  runtests     Build all tests and run them.')
+  print('  clean        Clean all the build files and directories.')
+  print('')
+  print('See also the comment in the script for typical usage.')
   sys.exit(1)
 
 
--- /src/build_tools/android_util.py
+++ /src/build_tools/android_util.py
@@ -548,7 +548,7 @@
   (devices_result, _) = process.communicate()
   used_ports = set(int(port) for port
                    in re.findall(r'emulator-(\d+)', devices_result))
-  return [port for port in xrange(5554, 5586, 2) if port not in used_ports]
+  return [port for port in range(5554, 5586, 2) if port not in used_ports]
 
 
 def SetUpTestingSdkHomeDirectory(dest_android_sdk_home,
@@ -575,7 +575,7 @@
           'create', 'avd',
           '--force',
           '--sdcard', '512M',]
-  for key, value in options.iteritems():
+  for key, value in options.items():
     args.extend([key, value])
   env = {'ANDROID_SDK_HOME': os.path.abspath(dest_android_sdk_home)}
   logging.info('Creating AVD: %s', args)
@@ -615,7 +615,7 @@
 def main():
   for arg in sys.argv[1:]:
     for item in sorted(GetApkProperties(arg).items()):
-      print '%s: %s' % item
+      print('%s: %s' % item)
 
 
 if __name__ == '__main__':
--- /src/build_tools/binary_size_checker.py
+++ /src/build_tools/binary_size_checker.py
@@ -70,12 +70,12 @@
   actual_size = os.stat(filename).st_size
   expected_size = EXPECTED_MAXIMUM_SIZES[basename]
   if actual_size < expected_size * 1024 * 1024:
-    print 'Pass: %s (size: %d) is smaller than expected (%d MB)' % (
-        filename, actual_size, expected_size)
+    print('Pass: %s (size: %d) is smaller than expected (%d MB)' % (
+        filename, actual_size, expected_size))
     return True
   else:
-    print 'WARNING: %s (size: %d) is larger than expected (%d MB)' % (
-        filename, actual_size, expected_size)
+    print('WARNING: %s (size: %d) is larger than expected (%d MB)' % (
+        filename, actual_size, expected_size))
     return False
 
 
--- /src/build_tools/build_and_sign_pkg_mac.py
+++ /src/build_tools/build_and_sign_pkg_mac.py
@@ -44,8 +44,8 @@
 import shutil
 import sys
 
-from util import PrintErrorAndExit
-from util import RunOrDie
+from .util import PrintErrorAndExit
+from .util import RunOrDie
 
 
 def ParseOption():
--- /src/build_tools/build_breakpad.py
+++ /src/build_tools/build_breakpad.py
@@ -54,9 +54,9 @@
   try:
     subprocess.check_output(command)
   except subprocess.CalledProcessError as e:
-    print e.output
+    print(e.output)
     sys.exit(e.returncode)
-  print 'Done: %s' % ' '.join(command)
+  print('Done: %s' % ' '.join(command))
 
 
 def Xcodebuild(projdir, target, arch, sdk, outdir):
--- /src/build_tools/build_diskimage_mac.py
+++ /src/build_tools/build_diskimage_mac.py
@@ -90,7 +90,7 @@
   # setup volume directory
   temp_dir = tempfile.mkdtemp()
   CopyFile(path.join(build_dir, ".keystone_install"), temp_dir)
-  os.chmod(path.join(temp_dir, ".keystone_install"), 0755) # rwxr-xr-x
+  os.chmod(path.join(temp_dir, ".keystone_install"), 0o755) # rwxr-xr-x
   for a in args:
     CopyFile(path.join(build_dir, a), temp_dir)
 
--- /src/build_tools/change_reference_mac.py
+++ /src/build_tools/change_reference_mac.py
@@ -41,8 +41,8 @@
 import optparse
 import os
 
-from util import PrintErrorAndExit
-from util import RunOrDie
+from .util import PrintErrorAndExit
+from .util import RunOrDie
 
 
 def ParseOption():
--- /src/build_tools/code_generator_util.py
+++ /src/build_tools/code_generator_util.py
@@ -33,27 +33,26 @@
 __author__ = "hidehiko"
 
 import struct
-import types
 
 
 def ToCppStringLiteral(s):
   """Returns C-style string literal, or NULL if given s is None."""
   if s is None:
-    return 'NULL'
+    return b'NULL'
 
-  if all(0x20 <= ord(c) <= 0x7E for c in s):
+  if all(0x20 <= c <= 0x7E for c in s):
     # All characters are in ascii code.
-    return '"%s"' % s.replace('\\', r'\\').replace('"', r'\"')
+    return b'"%b"' % s.replace(b'\\', br'\\').replace(b'"', br'\"')
   else:
     # One or more characters are non-ascii.
-    return '"%s"' % ''.join(r'\x%02X' % ord(c) for c in s)
+    return b'"%b"' % b''.join(br'\x%02X' % c for c in s)
 
 
 def FormatWithCppEscape(format_text, *args):
   """Returns a string filling format with args."""
   literal_list = []
   for arg in args:
-    if isinstance(arg, (types.StringType, types.NoneType)):
+    if isinstance(arg, (bytes, type(None))):
       arg = ToCppStringLiteral(arg)
     literal_list.append(arg)
 
@@ -95,7 +94,7 @@
   if target_compiler and target_compiler.startswith('msvs'):
     stream.write('const uint64 k%s_data_wordtype[] = {\n' % variable_name)
 
-    for word_index in xrange(0, len(data), 8):
+    for word_index in range(0, len(data), 8):
       word_chunk = data[word_index:word_index + 8].ljust(8, '\x00')
       stream.write('0x%016X, ' % struct.unpack('<Q', word_chunk))
       if (word_index / 8) % 4 == 3:
@@ -111,7 +110,7 @@
     stream.write('const char k%s_data[] =\n' % variable_name)
     # Output 16bytes per line.
     chunk_size = 16
-    for index in xrange(0, len(data), chunk_size):
+    for index in range(0, len(data), chunk_size):
       chunk = data[index:index + chunk_size]
       stream.write('"')
       stream.writelines(r'\x%02X' % ord(c) for c in chunk)
@@ -126,36 +125,50 @@
   if type(codepoint_list) is int:
     codepoint_list = (codepoint_list,)
   if codepoint_list is None or len(codepoint_list) == 0:
-    return 'null'
-  result = r'"'
+    return b'null'
+  result = b'"'
   for codepoint in codepoint_list:
-    utf16_string = unichr(codepoint).encode('utf-16be')
+    utf16_string = chr(codepoint).encode('utf-16be')
     if len(utf16_string) == 2:
       (u0, l0) = utf16_string
-      result += r'\u%02X%02X' % (ord(u0), ord(l0))
+      result += br'\u%02X%02X' % (u0, l0)
     else:
       (u0, l0, u1, l1) = utf16_string
-      result += r'\u%02X%02X\u%02X%02X' % (ord(u0), ord(l0), ord(u1), ord(l1))
-  result += r'"'
+      result += br'\u%02X%02X\u%02X%02X' % (u0, l0, u1, l1)
+  result += b'"'
   return result
 
 
 def SkipLineComment(stream, comment_prefix='#'):
   """Skips line comments from stream."""
   for line in stream:
+    if isinstance(line, bytes):
+      if isinstance(comment_prefix, str):
+        comment_prefix = comment_prefix.encode('utf-8')
+      line_ending = b'\n'
+    else:
+      line_ending = '\n'
     stripped_line = line.strip()
     if stripped_line and not stripped_line.startswith(comment_prefix):
-      yield line.rstrip('\n')
+      yield line.rstrip(line_ending)
 
 
 def ParseColumnStream(stream, num_column=None, delimiter=None):
   """Returns parsed columns read from stream."""
   if num_column is None:
     for line in stream:
-      yield line.rstrip('\n').split(delimiter)
+      if isinstance(line, bytes):
+        line_ending = b'\n'
+      else:
+        line_ending = '\n'
+      yield line.rstrip(line_ending).split(delimiter)
   else:
     for line in stream:
-      yield line.rstrip('\n').split(delimiter)[:num_column]
+      if isinstance(line, bytes):
+        line_ending = b'\n'
+      else:
+        line_ending = '\n'
+      yield line.rstrip(line_ending).split(delimiter)[:num_column]
 
 
 def SelectColumn(stream, column_index):
@@ -172,5 +185,5 @@
   grouper extends the last chunk to make it an n-element chunk by adding
   appropriate value, but this returns truncated chunk.
   """
-  for index in xrange(0, len(iterable), n):
+  for index in range(0, len(iterable), n):
     yield iterable[index:index + n]
--- /src/build_tools/codesign_mac.py
+++ /src/build_tools/codesign_mac.py
@@ -46,17 +46,17 @@
 
 def RunOrDie(command):
   """Run the command, or die if it failed."""
-  print "Running: " + command
+  print("Running: " + command)
   try:
     output = subprocess.check_output(command, shell=True)
-    print >> sys.stderr, "=========="
-    print >> sys.stderr, "COMMAND: " + command
-    print >> sys.stderr, output
+    print("==========", file=sys.stderr)
+    print("COMMAND: " + command, file=sys.stderr)
+    print(output, file=sys.stderr)
   except subprocess.CalledProcessError as e:
-    print >> sys.stderr, "=========="
-    print >> sys.stderr, "ERROR: " + command
-    print >> sys.stderr, e.output
-    print >> sys.stderr, "=========="
+    print("==========", file=sys.stderr)
+    print("ERROR: " + command, file=sys.stderr)
+    print(e.output, file=sys.stderr)
+    print("==========", file=sys.stderr)
     sys.exit(1)
 
 
@@ -119,18 +119,18 @@
   (options, unused_args) = parser.parse_args()
 
   if not options.target:
-    print "Error: --target should be specified."
-    print parser.print_help()
+    print("Error: --target should be specified.")
+    print(parser.print_help())
     sys.exit(1)
 
   return options
 
 
 def DumpEnviron():
-  print "=== os.environ ==="
+  print("=== os.environ ===")
   for key in sorted(os.environ):
-    print "%s = %s" % (key, os.getenv(key))
-  print "=================="
+    print("%s = %s" % (key, os.getenv(key)))
+  print("==================")
 
 
 def main():
--- /src/build_tools/copy_dll_and_symbol.py
+++ /src/build_tools/copy_dll_and_symbol.py
@@ -38,7 +38,7 @@
 import os
 import shutil
 
-from util import PrintErrorAndExit
+from .util import PrintErrorAndExit
 
 def ParseOption():
   """Parse command line options."""
@@ -98,7 +98,7 @@
     if _GetLastModifiedTime(src) <= target_file_mtime:
       # Older file found. Ignore.
       continue
-    print 'Copying %s to %s' % (src, target_file_abspath)
+    print('Copying %s to %s' % (src, target_file_abspath))
     shutil.copy2(src, target_file_abspath)
     break
 
--- /src/build_tools/copy_file.py
+++ /src/build_tools/copy_file.py
@@ -52,7 +52,7 @@
   Args:
     message: The error message to be printed to stderr.
   """
-  print >>sys.stderr, message
+  print(message, file=sys.stderr)
   sys.exit(1)
 
 
--- /src/build_tools/copy_qt_frameworks_mac.py
+++ /src/build_tools/copy_qt_frameworks_mac.py
@@ -41,9 +41,9 @@
 import optparse
 import os
 
-from copy_file import CopyFiles
-from util import PrintErrorAndExit
-from util import RunOrDie
+from .copy_file import CopyFiles
+from .util import PrintErrorAndExit
+from .util import RunOrDie
 
 
 def ParseOption():
--- /src/build_tools/embed_file.py
+++ /src/build_tools/embed_file.py
@@ -46,10 +46,10 @@
 
 def _FormatAsUint64LittleEndian(s):
   """Formats a string as uint64 value in little endian order."""
-  for _ in xrange(len(s), 8):
-    s += '\0'
+  for _ in range(len(s), 8):
+    s += b'\0'
   s = s[::-1]  # Reverse the string
-  return '0x%s' % binascii.b2a_hex(s)
+  return b'0x%b' % binascii.b2a_hex(s)
 
 
 def main():
@@ -57,30 +57,30 @@
   with open(opts.input, 'rb') as infile:
     with open(opts.output, 'wb') as outfile:
       outfile.write(
-          '#ifdef MOZC_EMBEDDED_FILE_%(name)s\n'
-          '#error "%(name)s was already included or defined elsewhere"\n'
-          '#else\n'
-          '#define MOZC_EMBEDDED_FILE_%(name)s\n'
-          'const uint64 %(name)s_data[] = {\n'
-          % {'name': opts.name})
+          b'#ifdef MOZC_EMBEDDED_FILE_%(name)b\n'
+          b'#error "%(name)b was already included or defined elsewhere"\n'
+          b'#else\n'
+          b'#define MOZC_EMBEDDED_FILE_%(name)b\n'
+          b'const uint64 %(name)b_data[] = {\n'
+          % {b'name': opts.name.encode('utf-8')})
 
       while True:
         chunk = infile.read(8)
         if not chunk:
           break
-        outfile.write('  ')
+        outfile.write(b'  ')
         outfile.write(_FormatAsUint64LittleEndian(chunk))
-        outfile.write(',\n')
+        outfile.write(b',\n')
 
       outfile.write(
-          '};\n'
-          'const EmbeddedFile %(name)s = {\n'
-          '  %(name)s_data,\n'
-          '  %(size)d,\n'
-          '};\n'
-          '#endif  // MOZC_EMBEDDED_FILE_%(name)s\n'
-          % {'name': opts.name,
-             'size': os.stat(opts.input).st_size})
+          b'};\n'
+          b'const EmbeddedFile %(name)b = {\n'
+          b'  %(name)b_data,\n'
+          b'  %(size)d,\n'
+          b'};\n'
+          b'#endif  // MOZC_EMBEDDED_FILE_%(name)b\n'
+          % {b'name': opts.name.encode('utf-8'),
+             b'size': os.stat(opts.input).st_size})
 
 
 if __name__ == '__main__':
--- /src/build_tools/embed_pathname.py
+++ /src/build_tools/embed_pathname.py
@@ -28,7 +28,7 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-"""A script to embed the given (relative) path name to C/C++ characters array.
+r"""A script to embed the given (relative) path name to C/C++ characters array.
 
 Example:
   ./embed_pathname.py --path_to_be_embedded=d:\data\mozc
@@ -53,7 +53,7 @@
 
   (options, unused_args) = parser.parse_args()
   if not all(vars(options).values()):
-    print parser.print_help()
+    print(parser.print_help())
     sys.exit(1)
 
   return options
@@ -63,7 +63,7 @@
   opt = ParseOption()
   path = os.path.abspath(opt.path_to_be_embedded)
   # TODO(yukawa): Consider the case of non-ASCII characters.
-  escaped_path = path.encode('string-escape')
+  escaped_path = path.replace('\\', '\\\\')
   with open(opt.output, 'w') as output_file:
     output_file.write(
         'const char %s[] = "%s";\n' % (opt.constant_name, escaped_path))
--- /src/build_tools/ensure_gyp_module_path.py
+++ /src/build_tools/ensure_gyp_module_path.py
@@ -48,7 +48,7 @@
 
   (options, _) = parser.parse_args()
   if not options.expected:
-    print parser.print_help()
+    print(parser.print_help())
     sys.exit(1)
 
   return options
@@ -59,20 +59,20 @@
   opt = ParseOption()
   expected_path = os.path.abspath(opt.expected)
   if not os.path.exists(expected_path):
-    print '%s does not exist.' % expected_path
+    print('%s does not exist.' % expected_path)
     sys.exit(1)
 
   try:
     import gyp  # NOLINT
   except ImportError as e:
-    print 'import gyp failed: %s' % e
+    print('import gyp failed: %s' % e)
     sys.exit(1)
 
   actual_path = os.path.abspath(gyp.__path__[0])
   if expected_path != actual_path:
-    print 'Unexpected gyp module is loaded on this environment.'
-    print '  expected: %s' % expected_path
-    print '  actual  : %s' % actual_path
+    print('Unexpected gyp module is loaded on this environment.')
+    print('  expected: %s' % expected_path)
+    print('  actual  : %s' % actual_path)
     sys.exit(1)
 
 if __name__ == '__main__':
--- /src/build_tools/gen_win32_resource_header.py
+++ /src/build_tools/gen_win32_resource_header.py
@@ -39,7 +39,7 @@
 __author__ = "yukawa"
 
 import logging
-import mozc_version
+from . import mozc_version
 import optparse
 import os
 import sys
--- /src/build_tools/mozc_version.py
+++ /src/build_tools/mozc_version.py
@@ -94,7 +94,7 @@
   last_digit = TARGET_PLATFORM_TO_DIGIT.get(target_platform, None)
   if last_digit is None:
     logging.critical('target_platform %s is invalid. Accetable ones are %s',
-                     target_platform, TARGET_PLATFORM_TO_DIGIT.keys())
+                     target_platform, list(TARGET_PLATFORM_TO_DIGIT.keys()))
     sys.exit(1)
 
   if not revision:
@@ -314,13 +314,14 @@
     self._properties = {}
     if not os.path.isfile(path):
       return
-    for line in open(path):
-      matchobj = re.match(r'(\w+)=(.*)', line.strip())
-      if matchobj:
-        var = matchobj.group(1)
-        val = matchobj.group(2)
-        if var not in self._properties:
-          self._properties[var] = val
+    with open(path) as file:
+      for line in file:
+        matchobj = re.match(r'(\w+)=(.*)', line.strip())
+        if matchobj:
+          var = matchobj.group(1)
+          val = matchobj.group(2)
+          if var not in self._properties:
+            self._properties[var] = val
 
     # Check mandatory properties.
     for key in VERSION_PROPERTIES: