Modify isort config to prepare for black formatting (pantsbuild#8332)

### Problem

Currently, the formatting situation in the python code is quite painful as it involves manual formatting of code.
I would like to replace our current workflow with one involving Black in a subsequent PR (see motivations for the choice over there).
Black is opinionated about code layout, so with our current settings, Black and isort would be having minor opinion differences.

### Solution

Modify the isort configuration to bend to Black's taste.

### Result

Once we run Black on the codebase with a minimal configuration, isort will be happy with the results.

.isort.cfg

@@ -3,6 +3,10 @@
 
 [settings]
 line_length=100
+multi_line_output=3
+include_trailing_comma=True
+force_grid_wrap=0
+use_parentheses=true
 indent=2
 lines_after_imports=2
 known_first_party=internal_backend,pants,pants_test

examples/src/python/example/tensorflow_custom_op/setup.py

@@ -1,7 +1,8 @@
 # Copyright 2018 Pants project contributors (see CONTRIBUTORS.md).
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
-from setuptools import setup, find_packages
+from setuptools import find_packages, setup
+
 
 setup(
   name='tensorflow_custom_op',

pants-plugins/src/python/internal_backend/repositories/register.py

@@ -3,8 +3,12 @@
 
 import os
 
-from pants.backend.jvm.ossrh_publication_metadata import (Developer, License,
-                                                          OSSRHPublicationMetadata, Scm)
+from pants.backend.jvm.ossrh_publication_metadata import (
+  Developer,
+  License,
+  OSSRHPublicationMetadata,
+  Scm,
+)
 from pants.backend.jvm.repository import Repository
 from pants.build_graph.build_file_aliases import BuildFileAliases
 

src/python/pants/backend/codegen/thrift/python/register.py

@@ -2,8 +2,9 @@
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
 from pants.backend.codegen.thrift.python.apache_thrift_py_gen import ApacheThriftPyGen
-from pants.backend.codegen.thrift.python.py_thrift_namespace_clash_check import \
-  PyThriftNamespaceClashCheck
+from pants.backend.codegen.thrift.python.py_thrift_namespace_clash_check import (
+  PyThriftNamespaceClashCheck,
+)
 from pants.backend.codegen.thrift.python.python_thrift_library import PythonThriftLibrary
 from pants.build_graph.build_file_aliases import BuildFileAliases
 from pants.goal.task_registrar import TaskRegistrar as task

src/python/pants/backend/jvm/ivy_utils.py

@@ -13,8 +13,10 @@
 
 from twitter.common.collections import OrderedSet
 
-from pants.backend.jvm.subsystems.jar_dependency_management import (JarDependencyManagement,
-                                                                    PinnedJarArtifactSet)
+from pants.backend.jvm.subsystems.jar_dependency_management import (
+  JarDependencyManagement,
+  PinnedJarArtifactSet,
+)
 from pants.backend.jvm.targets.exportable_jvm_library import ExportableJvmLibrary
 from pants.backend.jvm.targets.jar_library import JarLibrary
 from pants.base.generator import Generator, TemplateData

src/python/pants/backend/jvm/register.py

@@ -2,8 +2,12 @@
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
 from pants.backend.jvm.artifact import Artifact
-from pants.backend.jvm.ossrh_publication_metadata import (Developer, License,
-                                                          OSSRHPublicationMetadata, Scm)
+from pants.backend.jvm.ossrh_publication_metadata import (
+  Developer,
+  License,
+  OSSRHPublicationMetadata,
+  Scm,
+)
 from pants.backend.jvm.repository import Repository as repo
 from pants.backend.jvm.scala_artifact import ScalaArtifact
 from pants.backend.jvm.subsystems.jar_dependency_management import JarDependencyManagementSetup
@@ -21,8 +25,10 @@
 from pants.backend.jvm.targets.jvm_app import JvmApp
 from pants.backend.jvm.targets.jvm_binary import Duplicate, JarRules, JvmBinary, Skip
 from pants.backend.jvm.targets.jvm_prep_command import JvmPrepCommand
-from pants.backend.jvm.targets.managed_jar_dependencies import (ManagedJarDependencies,
-                                                                ManagedJarLibraries)
+from pants.backend.jvm.targets.managed_jar_dependencies import (
+  ManagedJarDependencies,
+  ManagedJarLibraries,
+)
 from pants.backend.jvm.targets.scala_exclude import ScalaExclude
 from pants.backend.jvm.targets.scala_jar_dependency import ScalaJarDependency
 from pants.backend.jvm.targets.scala_library import ScalaLibrary
@@ -57,9 +63,11 @@
 from pants.backend.jvm.tasks.prepare_resources import PrepareResources
 from pants.backend.jvm.tasks.prepare_services import PrepareServices
 from pants.backend.jvm.tasks.provide_tools_jar import ProvideToolsJar
-from pants.backend.jvm.tasks.run_jvm_prep_command import (RunBinaryJvmPrepCommand,
-                                                          RunCompileJvmPrepCommand,
-                                                          RunTestJvmPrepCommand)
+from pants.backend.jvm.tasks.run_jvm_prep_command import (
+  RunBinaryJvmPrepCommand,
+  RunCompileJvmPrepCommand,
+  RunTestJvmPrepCommand,
+)
 from pants.backend.jvm.tasks.scala_repl import ScalaRepl
 from pants.backend.jvm.tasks.scaladoc_gen import ScaladocGen
 from pants.backend.jvm.tasks.scalafix import ScalaFixCheck, ScalaFixFix

src/python/pants/backend/jvm/targets/jvm_binary.py

@@ -8,8 +8,12 @@
 from pants.backend.jvm.targets.jvm_target import JvmTarget
 from pants.base.exceptions import TargetDefinitionException
 from pants.base.payload import Payload
-from pants.base.payload_field import (ExcludesField, FingerprintedField, FingerprintedMixin,
-                                      PrimitiveField)
+from pants.base.payload_field import (
+  ExcludesField,
+  FingerprintedField,
+  FingerprintedMixin,
+  PrimitiveField,
+)
 from pants.base.validation import assert_list
 from pants.java.jar.exclude import Exclude
 

src/python/pants/backend/jvm/tasks/coursier_resolve.py

@@ -9,8 +9,10 @@
 from urllib import parse
 
 from pants.backend.jvm.ivy_utils import IvyUtils
-from pants.backend.jvm.subsystems.jar_dependency_management import (JarDependencyManagement,
-                                                                    PinnedJarArtifactSet)
+from pants.backend.jvm.subsystems.jar_dependency_management import (
+  JarDependencyManagement,
+  PinnedJarArtifactSet,
+)
 from pants.backend.jvm.subsystems.resolve_subsystem import JvmResolveSubsystem
 from pants.backend.jvm.targets.jar_library import JarLibrary
 from pants.backend.jvm.targets.jvm_target import JvmTarget

src/python/pants/backend/jvm/tasks/jvm_compile/jvm_compile.py

@@ -15,13 +15,19 @@
 from pants.backend.jvm.targets.javac_plugin import JavacPlugin
 from pants.backend.jvm.targets.scalac_plugin import ScalacPlugin
 from pants.backend.jvm.tasks.classpath_products import ClasspathEntry
-from pants.backend.jvm.tasks.jvm_compile.class_not_found_error_patterns import \
-  CLASS_NOT_FOUND_ERROR_PATTERNS
+from pants.backend.jvm.tasks.jvm_compile.class_not_found_error_patterns import (
+  CLASS_NOT_FOUND_ERROR_PATTERNS,
+)
 from pants.backend.jvm.tasks.jvm_compile.compile_context import CompileContext
-from pants.backend.jvm.tasks.jvm_compile.execution_graph import (ExecutionFailure, ExecutionGraph,
-                                                                 Job)
-from pants.backend.jvm.tasks.jvm_compile.missing_dependency_finder import (CompileErrorExtractor,
-                                                                           MissingDependencyFinder)
+from pants.backend.jvm.tasks.jvm_compile.execution_graph import (
+  ExecutionFailure,
+  ExecutionGraph,
+  Job,
+)
+from pants.backend.jvm.tasks.jvm_compile.missing_dependency_finder import (
+  CompileErrorExtractor,
+  MissingDependencyFinder,
+)
 from pants.backend.jvm.tasks.jvm_dependency_analyzer import JvmDependencyAnalyzer
 from pants.backend.jvm.tasks.nailgun_task import NailgunTaskBase
 from pants.base.build_environment import get_buildroot
@@ -34,8 +40,14 @@
 from pants.option.ranked_value import RankedValue
 from pants.reporting.reporting_utils import items_to_report_element
 from pants.util.contextutil import Timer, temporary_dir
-from pants.util.dirutil import (fast_relpath, read_file, safe_delete, safe_file_dump, safe_mkdir,
-                                safe_rmtree)
+from pants.util.dirutil import (
+  fast_relpath,
+  read_file,
+  safe_delete,
+  safe_file_dump,
+  safe_mkdir,
+  safe_rmtree,
+)
 from pants.util.fileutil import create_size_estimators
 from pants.util.memo import memoized_method, memoized_property
 

src/python/pants/backend/jvm/tasks/jvm_compile/rsc/rsc_compile.py

@@ -18,8 +18,12 @@
 from pants.base.exceptions import TaskError
 from pants.base.workunit import WorkUnitLabel
 from pants.build_graph.mirrored_target_option_mixin import MirroredTargetOptionMixin
-from pants.engine.fs import (EMPTY_DIRECTORY_DIGEST, DirectoryToMaterialize, PathGlobs,
-                             PathGlobsAndRoot)
+from pants.engine.fs import (
+  EMPTY_DIRECTORY_DIGEST,
+  DirectoryToMaterialize,
+  PathGlobs,
+  PathGlobsAndRoot,
+)
 from pants.engine.isolated_process import ExecuteProcessRequest, FallibleExecuteProcessResult
 from pants.java.jar.jar_dependency import JarDependency
 from pants.reporting.reporting_utils import items_to_report_element

src/python/pants/backend/jvm/tasks/jvm_compile/zinc/zinc_compile.py

@@ -23,8 +23,12 @@
 from pants.base.exceptions import TaskError
 from pants.base.hash_utils import hash_file
 from pants.base.workunit import WorkUnitLabel
-from pants.engine.fs import (EMPTY_DIRECTORY_DIGEST, DirectoryToMaterialize, PathGlobs,
-                             PathGlobsAndRoot)
+from pants.engine.fs import (
+  EMPTY_DIRECTORY_DIGEST,
+  DirectoryToMaterialize,
+  PathGlobs,
+  PathGlobsAndRoot,
+)
 from pants.engine.isolated_process import ExecuteProcessRequest
 from pants.util.contextutil import open_zip
 from pants.util.dirutil import fast_relpath

src/python/pants/backend/jvm/tasks/jvmdoc_gen.py

@@ -12,8 +12,10 @@
 from pants.backend.jvm.tasks.jvm_task import JvmTask
 from pants.base.exceptions import TaskError
 from pants.build_graph.target_scopes import Scopes
-from pants.task.target_restriction_mixins import (HasSkipAndTransitiveOptionsMixin,
-                                                  SkipAndTransitiveOptionsRegistrar)
+from pants.task.target_restriction_mixins import (
+  HasSkipAndTransitiveOptionsMixin,
+  SkipAndTransitiveOptionsRegistrar,
+)
 from pants.util import desktop
 from pants.util.dirutil import safe_mkdir, safe_walk
 from pants.util.memo import memoized_property

src/python/pants/backend/native/register.py

@@ -7,8 +7,10 @@
 from pants.backend.native.subsystems.native_build_settings import NativeBuildSettings
 from pants.backend.native.subsystems.native_toolchain import create_native_toolchain_rules
 from pants.backend.native.subsystems.xcode_cli_tools import create_xcode_cli_tools_rules
-from pants.backend.native.targets.external_native_library import (ConanRequirement,
-                                                                  ExternalNativeLibrary)
+from pants.backend.native.targets.external_native_library import (
+  ConanRequirement,
+  ExternalNativeLibrary,
+)
 from pants.backend.native.targets.native_artifact import NativeArtifact
 from pants.backend.native.targets.native_library import CLibrary, CppLibrary
 from pants.backend.native.targets.packaged_native_library import PackagedNativeLibrary

src/python/pants/backend/native/subsystems/native_toolchain.py

@@ -2,8 +2,15 @@
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
 
-from pants.backend.native.config.environment import (Assembler, CCompiler, CppCompiler,
-                                                     CppToolchain, CToolchain, Linker, Platform)
+from pants.backend.native.config.environment import (
+  Assembler,
+  CCompiler,
+  CppCompiler,
+  CppToolchain,
+  CToolchain,
+  Linker,
+  Platform,
+)
 from pants.backend.native.subsystems.binaries.binutils import Binutils
 from pants.backend.native.subsystems.binaries.gcc import GCC
 from pants.backend.native.subsystems.binaries.llvm import LLVM

src/python/pants/backend/native/tasks/native_task.py

@@ -6,8 +6,10 @@
 from pants.backend.native.config.environment import CppToolchain, CToolchain
 from pants.backend.native.subsystems.native_build_settings import NativeBuildSettings
 from pants.backend.native.subsystems.native_build_step import NativeBuildStep
-from pants.backend.native.subsystems.native_toolchain import (NativeToolchain,
-                                                              ToolchainVariantRequest)
+from pants.backend.native.subsystems.native_toolchain import (
+  NativeToolchain,
+  ToolchainVariantRequest,
+)
 from pants.backend.native.targets.native_library import NativeLibrary
 from pants.backend.native.targets.packaged_native_library import PackagedNativeLibrary
 from pants.build_graph.dependency_context import DependencyContext

src/python/pants/backend/project_info/rules/source_file_validator_test.py

@@ -4,8 +4,11 @@
 import textwrap
 import unittest
 
-from pants.backend.project_info.rules.source_file_validator import (Matcher, MultiMatcher,
-                                                                    RegexMatchResult)
+from pants.backend.project_info.rules.source_file_validator import (
+  Matcher,
+  MultiMatcher,
+  RegexMatchResult,
+)
 
 
 # Note that some parts of these tests are just exercising various capabilities of the regex engine.

src/python/pants/backend/python/register.py

@@ -5,27 +5,34 @@
 from pants.backend.python.python_artifact import PythonArtifact
 from pants.backend.python.python_requirement import PythonRequirement
 from pants.backend.python.python_requirements import PythonRequirements
-from pants.backend.python.rules import (create_requirements_pex, download_pex_bin, inject_init,
-                                        python_test_runner)
+from pants.backend.python.rules import (
+  create_requirements_pex,
+  download_pex_bin,
+  inject_init,
+  python_test_runner,
+)
 from pants.backend.python.subsystems.python_native_code import PythonNativeCode
 from pants.backend.python.subsystems.python_native_code import rules as python_native_code_rules
 from pants.backend.python.subsystems.subprocess_environment import SubprocessEnvironment
-from pants.backend.python.subsystems.subprocess_environment import \
-  rules as subprocess_environment_rules
+from pants.backend.python.subsystems.subprocess_environment import (
+  rules as subprocess_environment_rules,
+)
 from pants.backend.python.targets.python_app import PythonApp
 from pants.backend.python.targets.python_binary import PythonBinary
 from pants.backend.python.targets.python_distribution import PythonDistribution
 from pants.backend.python.targets.python_library import PythonLibrary
 from pants.backend.python.targets.python_requirement_library import PythonRequirementLibrary
 from pants.backend.python.targets.python_tests import PythonTests
 from pants.backend.python.targets.unpacked_whls import UnpackedWheels
-from pants.backend.python.tasks.build_local_python_distributions import \
-  BuildLocalPythonDistributions
+from pants.backend.python.tasks.build_local_python_distributions import (
+  BuildLocalPythonDistributions,
+)
 from pants.backend.python.tasks.gather_sources import GatherSources
 from pants.backend.python.tasks.isort_prep import IsortPrep
 from pants.backend.python.tasks.isort_run import IsortRun
-from pants.backend.python.tasks.local_python_distribution_artifact import \
-  LocalPythonDistributionArtifact
+from pants.backend.python.tasks.local_python_distribution_artifact import (
+  LocalPythonDistributionArtifact,
+)
 from pants.backend.python.tasks.pytest_prep import PytestPrep
 from pants.backend.python.tasks.pytest_run import PytestRun
 from pants.backend.python.tasks.python_binary_create import PythonBinaryCreate

src/python/pants/backend/python/rules/python_test_runner.py

@@ -1,8 +1,10 @@
 # Copyright 2018 Pants project contributors (see CONTRIBUTORS.md).
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
-from pants.backend.python.rules.create_requirements_pex import (RequirementsPex,
-                                                                RequirementsPexRequest)
+from pants.backend.python.rules.create_requirements_pex import (
+  RequirementsPex,
+  RequirementsPexRequest,
+)
 from pants.backend.python.rules.inject_init import InjectedInitDigest
 from pants.backend.python.subsystems.pytest import PyTest
 from pants.backend.python.subsystems.python_setup import PythonSetup

src/python/pants/backend/python/tasks/build_local_python_distributions.py

@@ -13,8 +13,10 @@
 from pants.backend.native.tasks.link_shared_libraries import SharedLibrary
 from pants.backend.python.python_requirement import PythonRequirement
 from pants.backend.python.subsystems.pex_build_util import is_local_python_dist
-from pants.backend.python.subsystems.python_native_code import (BuildSetupRequiresPex,
-                                                                PythonNativeCode)
+from pants.backend.python.subsystems.python_native_code import (
+  BuildSetupRequiresPex,
+  PythonNativeCode,
+)
 from pants.backend.python.targets.python_requirement_library import PythonRequirementLibrary
 from pants.base.build_environment import get_buildroot
 from pants.base.exceptions import TargetDefinitionException, TaskError

src/python/pants/backend/python/tasks/coverage/plugin.py

@@ -4,8 +4,6 @@
 
 from __future__ import absolute_import, division, print_function, unicode_literals
 
-# NB: This file must keep Python 2 support because it is a resource that may be run with Python 2.
-
 import json
 import os
 
@@ -16,6 +14,11 @@
 from coverage.python import PythonFileReporter
 
 
+# NB: This file must keep Python 2 support because it is a resource that may be run with Python 2.
+
+
+
+
 class SimpleFileTracer(FileTracer):
   def __init__(self, filename):
     super(SimpleFileTracer, self).__init__()

src/python/pants/backend/python/tasks/gather_sources.py

@@ -8,8 +8,12 @@
 from pex.pex_builder import PEXBuilder
 from twitter.common.collections import OrderedSet
 
-from pants.backend.python.subsystems.pex_build_util import (PexBuilderWrapper, has_python_sources,
-                                                            has_resources, is_python_target)
+from pants.backend.python.subsystems.pex_build_util import (
+  PexBuilderWrapper,
+  has_python_sources,
+  has_resources,
+  is_python_target,
+)
 from pants.base.exceptions import TaskError
 from pants.invalidation.cache_manager import VersionedTargetSet
 from pants.task.task import Task