[BEAM-7372] cleanup codes for py2 from apache_beam/transforms (#14544)

sdks/python/apache_beam/transforms/__init__.py

@@ -18,7 +18,6 @@
 """PTransform and descendants."""
 
 # pylint: disable=wildcard-import
-from __future__ import absolute_import
 
 from apache_beam.transforms import combiners
 from apache_beam.transforms.core import *

sdks/python/apache_beam/transforms/combiners.py

@@ -19,17 +19,12 @@
 
 # pytype: skip-file
 
-from __future__ import absolute_import
-from __future__ import division
-
 import copy
 import heapq
 import operator
 import random
 import sys
 import warnings
-from builtins import object
-from builtins import zip
 from typing import Any
 from typing import Dict
 from typing import Iterable
@@ -39,8 +34,6 @@
 from typing import TypeVar
 from typing import Union
 
-from past.builtins import long
-
 from apache_beam import typehints
 from apache_beam.transforms import core
 from apache_beam.transforms import cy_combiners
@@ -96,7 +89,7 @@ def expand(self, pcoll):
 
 # TODO(laolu): This type signature is overly restrictive. This should be
 # more general.
-@with_input_types(Union[float, int, long])
+@with_input_types(Union[float, int])
 @with_output_types(float)
 class MeanCombineFn(core.CombineFn):
   """CombineFn for computing an arithmetic mean."""

sdks/python/apache_beam/transforms/combiners_test.py

@@ -18,15 +18,11 @@
 """Unit tests for our libraries of combine PTransforms."""
 # pytype: skip-file
 
-from __future__ import absolute_import
-from __future__ import division
-
 import itertools
 import random
 import unittest
 
 import hamcrest as hc
-from future.builtins import range
 from nose.plugins.attrib import attr
 
 import apache_beam as beam

sdks/python/apache_beam/transforms/core.py

@@ -19,19 +19,12 @@
 
 # pytype: skip-file
 
-from __future__ import absolute_import
-
 import copy
 import inspect
 import logging
 import random
 import types
 import typing
-from builtins import map
-from builtins import object
-from builtins import range
-
-from past.builtins import unicode
 
 from apache_beam import coders
 from apache_beam import pvalue
@@ -80,11 +73,6 @@
   from apache_beam.transforms.trigger import DefaultTrigger
   from apache_beam.transforms.trigger import TriggerFn
 
-try:
-  import funcsigs  # Python 2 only.
-except ImportError:
-  funcsigs = None
-
 __all__ = [
     'DoFn',
     'CombineFn',
@@ -385,12 +373,7 @@ def get_function_args_defaults(f):
     it doesn't include bound arguments and may follow function wrappers.
   """
   signature = get_signature(f)
-  # Fall back on funcsigs if inspect module doesn't have 'Parameter'; prefer
-  # inspect.Parameter over funcsigs.Parameter if both are available.
-  try:
-    parameter = inspect.Parameter
-  except AttributeError:
-    parameter = funcsigs.Parameter
+  parameter = inspect.Parameter
   # TODO(BEAM-5878) support kwonlyargs on Python 3.
   _SUPPORTED_ARG_TYPES = [
       parameter.POSITIONAL_ONLY, parameter.POSITIONAL_OR_KEYWORD
@@ -1618,18 +1601,10 @@ def MapTuple(fn, *args, **kwargs):  # pylint: disable=invalid-name
 
       beam.MapTuple(lambda a, b, ...: ...)
 
-  is equivalent to Python 2
-
-      beam.Map(lambda (a, b, ...), ...: ...)
-
   In other words
 
       beam.MapTuple(fn)
 
-  is equivalent to
-
-      beam.Map(lambda element, ...: fn(\*element, ...))
-
   This can be useful when processing a PCollection of tuples
   (e.g. key-value pairs).
 
@@ -2904,7 +2879,7 @@ def __init__(self, values, reshuffle=True):
       values: An object of values for the PCollection
     """
     super(Create, self).__init__()
-    if isinstance(values, (unicode, str, bytes)):
+    if isinstance(values, (str, bytes)):
       raise TypeError(
           'PTransform Create: Refusing to treat string as '
           'an iterable. (string=%r)' % values)

sdks/python/apache_beam/transforms/create_source.py

@@ -17,13 +17,6 @@
 
 # pytype: skip-file
 
-from __future__ import absolute_import
-from __future__ import division
-
-from builtins import map
-from builtins import next
-from builtins import range
-
 from apache_beam.io import iobase
 from apache_beam.transforms.core import Create
 

sdks/python/apache_beam/transforms/create_test.py

@@ -18,12 +18,8 @@
 """Unit tests for the Create and _CreateSource classes."""
 # pytype: skip-file
 
-from __future__ import absolute_import
-from __future__ import division
-
 import logging
 import unittest
-from builtins import range
 
 from apache_beam import Create
 from apache_beam.coders import FastPrimitivesCoder

sdks/python/apache_beam/transforms/cy_combiners.py

@@ -24,11 +24,7 @@
 
 # pytype: skip-file
 
-from __future__ import absolute_import
-from __future__ import division
-
 import operator
-from builtins import object
 
 from apache_beam.transforms import core
 

sdks/python/apache_beam/transforms/dataflow_distribution_counter_test.py

@@ -16,8 +16,6 @@
 
 # pytype: skip-file
 
-from __future__ import absolute_import
-
 import unittest
 
 from mock import Mock

sdks/python/apache_beam/transforms/deduplicate.py

@@ -19,9 +19,6 @@
 
 """a collection of ptransforms for deduplicating elements."""
 
-from __future__ import absolute_import
-from __future__ import division
-
 import typing
 
 from apache_beam import typehints

sdks/python/apache_beam/transforms/deduplicate_test.py

@@ -19,8 +19,6 @@
 
 """Unit tests for deduplicate transform by using TestStream."""
 
-from __future__ import absolute_import
-
 import unittest
 
 from nose.plugins.attrib import attr

sdks/python/apache_beam/transforms/display.py

@@ -38,19 +38,14 @@
 
 # pytype: skip-file
 
-from __future__ import absolute_import
-
 import calendar
 import inspect
 import json
-from builtins import object
 from datetime import datetime
 from datetime import timedelta
 from typing import TYPE_CHECKING
 from typing import List
 
-from past.builtins import unicode
-
 from apache_beam.portability import common_urns
 from apache_beam.portability.api import beam_runner_api_pb2
 
@@ -231,7 +226,6 @@ class DisplayDataItem(object):
   """
   typeDict = {
       str: 'STRING',
-      unicode: 'STRING',
       int: 'INTEGER',
       float: 'FLOAT',
       bool: 'BOOLEAN',

sdks/python/apache_beam/transforms/display_test.py

@@ -19,15 +19,12 @@
 
 # pytype: skip-file
 
-from __future__ import absolute_import
-
 import unittest
 from datetime import datetime
 
 # pylint: disable=ungrouped-imports
 import hamcrest as hc
 from hamcrest.core.base_matcher import BaseMatcher
-from past.builtins import unicode
 
 import apache_beam as beam
 from apache_beam.options.pipeline_options import PipelineOptions
@@ -167,7 +164,7 @@ def test_unicode_type_display_data(self):
     class MyDoFn(beam.DoFn):
       def display_data(self):
         return {
-            'unicode_string': unicode('my string'),
+            'unicode_string': 'my string',
             'unicode_literal_string': u'my literal string'
         }
 

sdks/python/apache_beam/transforms/dofn_lifecycle_test.py

@@ -19,8 +19,6 @@
 
 # pytype: skip-file
 
-from __future__ import absolute_import
-
 import unittest
 
 from nose.plugins.attrib import attr

sdks/python/apache_beam/transforms/environments.py

@@ -21,8 +21,6 @@
 
 # pytype: skip-file
 
-from __future__ import absolute_import
-
 import json
 import logging
 import sys

sdks/python/apache_beam/transforms/environments_test.py

@@ -20,8 +20,6 @@
 
 # pytype: skip-file
 
-from __future__ import absolute_import
-
 import logging
 import unittest
 

sdks/python/apache_beam/transforms/external.py

@@ -21,9 +21,6 @@
 """
 # pytype: skip-file
 
-from __future__ import absolute_import
-from __future__ import print_function
-
 import contextlib
 import copy
 import functools
@@ -150,8 +147,6 @@ def _get_named_tuple_instance(self):
 class AnnotationBasedPayloadBuilder(SchemaBasedPayloadBuilder):
   """
   Build a payload based on an external transform's type annotations.
-
-  Supported in python 3 only.
   """
   def __init__(self, transform, **values):
     """
@@ -174,8 +169,6 @@ def _get_named_tuple_instance(self):
 class DataclassBasedPayloadBuilder(SchemaBasedPayloadBuilder):
   """
   Build a payload based on an external transform that uses dataclasses.
-
-  Supported in python 3 only.
   """
   def __init__(self, transform):
     """

sdks/python/apache_beam/transforms/external_it_test.py

@@ -19,8 +19,6 @@
 
 # pytype: skip-file
 
-from __future__ import absolute_import
-
 import unittest
 
 from nose.plugins.attrib import attr

sdks/python/apache_beam/transforms/external_java.py

@@ -17,16 +17,13 @@
 
 """Tests for the Java external transforms."""
 
-from __future__ import absolute_import
-
 import argparse
 import logging
 import subprocess
 import sys
 
 import grpc
 from mock import patch
-from past.builtins import unicode
 
 import apache_beam as beam
 from apache_beam.options.pipeline_options import PipelineOptions
@@ -139,7 +136,7 @@ def run_pipeline(pipeline_options, expansion_service, wait_until_finish=True):
     res = (
         p
         | beam.Create(list('aaabccxyyzzz'))
-        | beam.Map(unicode)
+        | beam.Map(str)
         | beam.ExternalTransform(
             TEST_FILTER_URN,
             ImplicitSchemaPayloadBuilder({'data': u'middle'}),