Add Flake8 and isort config files (#12)

We need these config files for a followup change. 

It's also a good demo of how to hook up config files.

Author: Eric-Arellano

.flake8

@@ -0,0 +1,5 @@
+[flake8]
+extend-ignore:
+  E203,  # whitespace before ':' (conflicts with Black)
+  E231,  # Bad trailing comma (conflicts with Black)
+  E501,  # line too long (conflicts with Black)

.isort.cfg

@@ -0,0 +1,11 @@
+[settings]
+# This is to make isort compatible with Black. See
+# https://black.readthedocs.io/en/stable/the_black_code_style.html#how-black-wraps-lines.
+line_length=88
+multi_line_output=3
+include_trailing_comma=True
+force_grid_wrap=0
+use_parentheses=True
+
+known_first_party=helloworld
+default_section=THIRDPARTY

.travis.yml

@@ -10,6 +10,7 @@ env:
 os: linux
 dist: bionic
 language: python
+python: 3.7
 
 cache:
   directories:

helloworld/greet/BUILD

@@ -1,28 +1,24 @@
 # Copyright 2020 Pants project contributors.
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
-
 python_library(
-    # name defaults to the name of this directory, i.e., `greet`.
-    # sources defaults to ['*.py', '!*_test.py', '!test_*.py', '!conftest.py'].
+    # `name` defaults to the name of this directory, i.e., `greet`.
+    # `sources` defaults to ['*.py', '!*_test.py', '!test_*.py', '!conftest.py'].
     dependencies = [
         "//:translate",
         ":greetings",
         "helloworld/util"
     ],
-    compatibility = ">=3.6",
 )
 
-
 python_tests(
     name = 'tests',
-    # sources defaults to ['*_test.py', 'test_*.py', 'conftest.py'].
+    # `sources` defaults to ['*_test.py', 'test_*.py', 'conftest.py'].
     dependencies = [
         ":greet"
     ]
 )
 
-
 resources(
     name = 'greetings',
     sources = ['greetings.txt'],

helloworld/main.py

@@ -2,6 +2,7 @@
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
 from colors import green
+
 from helloworld.greet.greeting import Greeter
 
 

helloworld/main_py2.py

@@ -2,6 +2,7 @@
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
 from colors import green
+
 from helloworld.greet_py2.greeting_py2 import greet_py2
 
 

helloworld/util/lang.py

@@ -3,9 +3,10 @@
 
 import random
 
-from helloworld.util.resources import get_lines
 from translate import Translator
 
+from helloworld.util.resources import get_lines
+
 
 class LanguageTranslator:
     class UnknownLanguage(Exception):

helloworld/util/lang_test.py

@@ -2,6 +2,7 @@
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
 import pytest
+
 from helloworld.util.lang import LanguageTranslator
 
 

pants.ci.toml

@@ -14,10 +14,3 @@ process_execution_local_parallelism = 4
 # party dependencies. The total level of parallelism will be
 # `process_execution_local_parallelism x resolver_jobs`.
 resolver_jobs = 1
-
-[lint]
-# We use `per_target_caching` because we have some Python 2-only targets and some Python 3-only
-# targets, so we need to run each target as a separate process to avoid interpreter compatibility
-# conflicts. If you only have one Python version in your repository, do not use this setting. See
-# https://pants.readme.io/docs/python-lint-goal.
-per_target_caching = true

pants.toml

@@ -22,18 +22,29 @@ backend_packages2 = [
 # List v2 plugins here.
 plugins2 = []
 
-
 [source]
 # The Python source root is the repo root. See https://pants.readme.io/docs/source-roots.
 source_roots = """{
   '': ('python',),
 }"""
 
-
 [python-setup]
 # The default interpreter compatibility for code in this repo. Individual targets can ovverride
 #  this with the `compatibility` field. See
 #  https://pants.readme.io/docs/python-interpreter-compatibility.
 interpreter_constraints = [">=3.7"]
 # Use a lockfile. See https://pants.readme.io/docs/python-third-party-dependencies.
 requirement_constraints = "constraints.txt"
+
+[lint]
+# We use `per_target_caching` because we have some Python 2-only targets and some Python 3-only
+# targets, so we need to run each target as a separate process to avoid interpreter compatibility
+# conflicts. If you only have one Python version in your repository, do not use this setting. See
+# https://pants.readme.io/docs/python-lint-goal.
+per_target_caching = true
+
+[flake8]
+config = ".flake8"
+
+[isort]
+config = [".isort.cfg"]