diff --git a/conformance/update_failure_list.py b/conformance/update_failure_list.py
index 63f453df1b..ad42ed3c18 100755
--- a/conformance/update_failure_list.py
+++ b/conformance/update_failure_list.py
@@ -35,7 +35,6 @@ This is sort of like comm(1), except it recognizes comments and ignores them.
 """
 
 import argparse
-import fileinput
 
 parser = argparse.ArgumentParser(
     description='Adds/removes failures from the failure list.')
@@ -62,7 +61,8 @@ for remove_file in (args.remove_list or []):
 
 add_list = sorted(add_set, reverse=True)
 
-existing_list = file(args.filename).read()
+with open(args.filename) as in_file:
+    existing_list = in_file.read()
 
 with open(args.filename, "w") as f:
   for line in existing_list.splitlines(True):
diff --git a/examples/add_person.py b/examples/add_person.py
index 0b6985792d..aa0fbca737 100755
--- a/examples/add_person.py
+++ b/examples/add_person.py
@@ -5,6 +5,12 @@
 import addressbook_pb2
 import sys
 
+try:
+  raw_input          # Python 2
+except NameError:
+  raw_input = input  # Python 3
+
+
 # This function fills in a Person message based on user input.
 def PromptForAddress(person):
   person.id = int(raw_input("Enter person ID number: "))
@@ -30,13 +36,14 @@ def PromptForAddress(person):
     elif type == "work":
       phone_number.type = addressbook_pb2.Person.WORK
     else:
-      print "Unknown phone type; leaving as default value."
+      print("Unknown phone type; leaving as default value.")
+
 
 # Main procedure:  Reads the entire address book from a file,
 #   adds one person based on user input, then writes it back out to the same
 #   file.
 if len(sys.argv) != 2:
-  print "Usage:", sys.argv[0], "ADDRESS_BOOK_FILE"
+  print("Usage:", sys.argv[0], "ADDRESS_BOOK_FILE")
   sys.exit(-1)
 
 address_book = addressbook_pb2.AddressBook()
@@ -46,7 +53,7 @@ try:
   with open(sys.argv[1], "rb") as f:
     address_book.ParseFromString(f.read())
 except IOError:
-  print sys.argv[1] + ": File not found.  Creating a new file."
+  print(sys.argv[1] + ": File not found.  Creating a new file.")
 
 # Add an address.
 PromptForAddress(address_book.people.add())
diff --git a/examples/list_people.py b/examples/list_people.py
index f131872d84..d2c294c6f5 100755
--- a/examples/list_people.py
+++ b/examples/list_people.py
@@ -2,30 +2,33 @@
 
 # See README.txt for information and build instructions.
 
+from __future__ import print_function
 import addressbook_pb2
 import sys
 
+
 # Iterates though all people in the AddressBook and prints info about them.
 def ListPeople(address_book):
   for person in address_book.people:
-    print "Person ID:", person.id
-    print "  Name:", person.name
+    print("Person ID:", person.id)
+    print("  Name:", person.name)
     if person.email != "":
-      print "  E-mail address:", person.email
+      print("  E-mail address:", person.email)
 
     for phone_number in person.phones:
       if phone_number.type == addressbook_pb2.Person.MOBILE:
-        print "  Mobile phone #:",
+        print("  Mobile phone #:", end=" ")
       elif phone_number.type == addressbook_pb2.Person.HOME:
-        print "  Home phone #:",
+        print("  Home phone #:", end=" ")
       elif phone_number.type == addressbook_pb2.Person.WORK:
-        print "  Work phone #:",
-      print phone_number.number
+        print("  Work phone #:", end=" ")
+      print(phone_number.number)
+
 
 # Main procedure:  Reads the entire address book from a file and prints all
 #   the information inside.
 if len(sys.argv) != 2:
-  print "Usage:", sys.argv[0], "ADDRESS_BOOK_FILE"
+  print("Usage:", sys.argv[0], "ADDRESS_BOOK_FILE")
   sys.exit(-1)
 
 address_book = addressbook_pb2.AddressBook()
diff --git a/jenkins/make_test_output.py b/jenkins/make_test_output.py
index b1f2e2c0bb..985368534c 100644
--- a/jenkins/make_test_output.py
+++ b/jenkins/make_test_output.py
@@ -17,11 +17,12 @@ detailed test results.  It runs as the last step before the Jenkins build
 finishes.
 """
 
-import os;
-import sys;
+import os
+import sys
 from yattag import Doc
 from collections import defaultdict
 
+
 def readtests(basedir):
   tests = defaultdict(dict)
 
@@ -68,6 +69,7 @@ def readtests(basedir):
 
   return ret
 
+
 def genxml(tests):
   doc, tag, text = Doc().tagtext()
 
@@ -86,6 +88,7 @@ def genxml(tests):
 
   return doc.getvalue()
 
+
 sys.stderr.write("make_test_output.py: writing XML from directory: " +
-                 sys.argv[1] + "\n");
-print genxml(readtests(sys.argv[1]))
+                 sys.argv[1] + "\n")
+print(genxml(readtests(sys.argv[1])))
diff --git a/objectivec/DevTools/pddm.py b/objectivec/DevTools/pddm.py
index 9a11fec449..0b5b7b406d 100755
--- a/objectivec/DevTools/pddm.py
+++ b/objectivec/DevTools/pddm.py
@@ -124,6 +124,7 @@ def _MacroRefRe(macro_names):
   return re.compile(r'\b(?P<macro_ref>(?P<name>(%s))\((?P<args>.*?)\))' %
                     '|'.join(macro_names))
 
+
 def _MacroArgRefRe(macro_arg_names):
   # Takes in a list of macro arg names and makes a regex that will match
   # uses of those args.
@@ -318,25 +319,26 @@ class MacroCollection(object):
       return macro.body
     assert len(arg_values) == len(macro.args)
     args = dict(zip(macro.args, arg_values))
+
     def _lookupArg(match):
       val = args[match.group('name')]
       opt = match.group('option')
       if opt:
-        if opt == 'S': # Spaces for the length
+        if opt == 'S':  # Spaces for the length
           return ' ' * len(val)
-        elif opt == 'l': # Lowercase first character
+        elif opt == 'l':  # Lowercase first character
           if val:
             return val[0].lower() + val[1:]
           else:
             return val
-        elif opt == 'L': # All Lowercase
+        elif opt == 'L':  # All Lowercase
           return val.lower()
-        elif opt == 'u': # Uppercase first character
+        elif opt == 'u':  # Uppercase first character
           if val:
             return val[0].upper() + val[1:]
           else:
             return val
-        elif opt == 'U': # All Uppercase
+        elif opt == 'U':  # All Uppercase
           return val.upper()
         else:
           raise PDDMError('Unknown arg option "%s$%s" while expanding "%s".%s'
@@ -350,6 +352,7 @@ class MacroCollection(object):
 
   def _EvalMacrosRefs(self, text, macro_stack):
     macro_ref_re = _MacroRefRe(self._macros.keys())
+
     def _resolveMacro(match):
       return self._Expand(match, macro_stack)
     return macro_ref_re.sub(_resolveMacro, text)
@@ -496,9 +499,10 @@ class SourceFile(object):
       # Add the ending marker.
       if len(captured_lines) == 1:
         result.append('//%%PDDM-EXPAND-END %s' %
-                       captured_lines[0][directive_len:].strip())
+                      captured_lines[0][directive_len:].strip())
       else:
-        result.append('//%%PDDM-EXPAND-END (%s expansions)' % len(captured_lines))
+        result.append('//%%PDDM-EXPAND-END (%s expansions)' %
+                      len(captured_lines))
 
       return result
 
@@ -669,15 +673,15 @@ def main(args):
 
     if src_file.processed_content != src_file.original_content:
       if not opts.dry_run:
-        print 'Updating for "%s".' % a_path
+        print('Updating for "%s".' % a_path)
         with open(a_path, 'w') as f:
           f.write(src_file.processed_content)
       else:
         # Special result to indicate things need updating.
-        print 'Update needed for "%s".' % a_path
+        print('Update needed for "%s".' % a_path)
         result = 1
     elif opts.verbose:
-      print 'No update for "%s".' % a_path
+      print('No update for "%s".' % a_path)
 
   return result
 
diff --git a/python/google/protobuf/internal/test_util.py b/python/google/protobuf/internal/test_util.py
index 269d0e2d4f..9434b7b11e 100755
--- a/python/google/protobuf/internal/test_util.py
+++ b/python/google/protobuf/internal/test_util.py
@@ -39,11 +39,15 @@ __author__ = 'robinson@google.com (Will Robinson)'
 import numbers
 import operator
 import os.path
-import sys
 
 from google.protobuf import unittest_import_pb2
 from google.protobuf import unittest_pb2
-from google.protobuf import descriptor_pb2
+
+try:
+    long        # Python 2
+except NameError:
+    long = int  # Python 3
+
 
 # Tests whether the given TestAllTypes message is proto2 or not.
 # This is used to gate several fields/features that only exist
@@ -51,6 +55,7 @@ from google.protobuf import descriptor_pb2
 def IsProto2(message):
   return message.DESCRIPTOR.syntax == "proto2"
 
+
 def SetAllNonLazyFields(message):
   """Sets every non-lazy field in the message to a unique value.
 
@@ -707,8 +712,8 @@ class NonStandardInteger(numbers.Integral):
   NonStandardInteger is the minimal legal specification for a custom Integral.
   As such, it does not support 0 < x < 5 and it is not hashable.
 
-  Note: This is added here instead of relying on numpy or a similar library with
-  custom integers to limit dependencies.
+  Note: This is added here instead of relying on numpy or a similar library
+  with custom integers to limit dependencies.
   """
 
   def __init__(self, val, error_string_on_conversion=None):
@@ -845,4 +850,3 @@ class NonStandardInteger(numbers.Integral):
 
   def __repr__(self):
     return 'NonStandardInteger(%s)' % self.val
-