Add black formatter for Python code

.git-blame-ignore-revs

@@ -0,0 +1,4 @@
+# $ git config blame.ignoreRevsFile .git-blame-ignore-revs
+
+# Migrate code style to Black
+41ccd65e2e659aa0add0e5ab59f1a46e32cc4c46

.github/workflows/black.yml

@@ -0,0 +1,28 @@
+# This is a workflow to format Python code with black formatter
+
+name: black
+
+# Controls when the action will run. Triggers the workflow on push or pull request
+# events but only for the master branch
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+# A workflow run is made up of one or more jobs that can run sequentially or in parallel
+jobs:
+  # This workflow contains a single job called "black"
+  black:
+    # The type of runner that the job will run on
+    runs-on: ubuntu-latest
+
+    # Steps represent a sequence of tasks that will be executed as part of the job
+    steps:
+      # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
+      - uses: actions/checkout@v2
+      # Set up a Python environment for use in actions
+      - uses: actions/setup-python@v2
+
+      # Run black code formatter
+      - uses: psf/black@stable

CONTRIBUTING.md

@@ -1 +1,10 @@
-Coming soon
+# Python code style
+
+## black
+
+We use [black](https://black.readthedocs.io/en/stable/) code formatter.
+
+- Revision: `20.8b1` or branch `stable`.
+- See configuration in `pyproject.toml`.
+
+Run before each commit: `black .`

README.md

@@ -1,3 +1,5 @@
+[![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/psf/black)
+
 What?
 ====
 A lightweight Python package exposing a subset of OpenCL and SYCL

dpctl/__init__.py

@@ -22,7 +22,7 @@
 ## This top-level dpctl module.
 ##
 ##===----------------------------------------------------------------------===##
-'''
+"""
     Data Parallel Control (dpCtl)
 
     dpCtl provides a lightweight Python abstraction over DPC++/SYCL and
@@ -43,12 +43,13 @@
 
     Please use `pydoc dpctl.ocldrv` to look at the current API for dpctl.ocldrv.
 
-'''
+"""
 __author__ = "Intel Corp."
 
 from ._sycl_core import *
 from ._version import get_versions
 
+
 def get_include():
     """
     Return the directory that contains the dpCtl *.h header files.
@@ -57,7 +58,9 @@ def get_include():
     this function to locate the appropriate include directory.
     """
     import os.path
-    return os.path.join(os.path.dirname(__file__), 'include')
 
-__version__ = get_versions()['version']
+    return os.path.join(os.path.dirname(__file__), "include")
+
+
+__version__ = get_versions()["version"]
 del get_versions

dpctl/_version.py

@@ -1,4 +1,3 @@
-
 # This file helps to compute a version number in source trees obtained from
 # git-archive tarball (such as those provided by githubs download-from-tag
 # feature). Distribution tarballs (built by setup.py sdist) and build
@@ -58,28 +57,32 @@ class NotThisMethod(Exception):
 
 def register_vcs_handler(vcs, method):  # decorator
     """Decorator to mark a method as the handler for a particular VCS."""
+
     def decorate(f):
         """Store f in HANDLERS[vcs][method]."""
         if vcs not in HANDLERS:
             HANDLERS[vcs] = {}
         HANDLERS[vcs][method] = f
         return f
+
     return decorate
 
 
-def run_command(commands, args, cwd=None, verbose=False, hide_stderr=False,
-                env=None):
+def run_command(commands, args, cwd=None, verbose=False, hide_stderr=False, env=None):
     """Call the given command(s)."""
     assert isinstance(commands, list)
     p = None
     for c in commands:
         try:
             dispcmd = str([c] + args)
             # remember shell=False, so use git.cmd on windows, not just git
-            p = subprocess.Popen([c] + args, cwd=cwd, env=env,
-                                 stdout=subprocess.PIPE,
-                                 stderr=(subprocess.PIPE if hide_stderr
-                                         else None))
+            p = subprocess.Popen(
+                [c] + args,
+                cwd=cwd,
+                env=env,
+                stdout=subprocess.PIPE,
+                stderr=(subprocess.PIPE if hide_stderr else None),
+            )
             break
         except EnvironmentError:
             e = sys.exc_info()[1]
@@ -116,16 +119,22 @@ def versions_from_parentdir(parentdir_prefix, root, verbose):
     for i in range(3):
         dirname = os.path.basename(root)
         if dirname.startswith(parentdir_prefix):
-            return {"version": dirname[len(parentdir_prefix):],
-                    "full-revisionid": None,
-                    "dirty": False, "error": None, "date": None}
+            return {
+                "version": dirname[len(parentdir_prefix) :],
+                "full-revisionid": None,
+                "dirty": False,
+                "error": None,
+                "date": None,
+            }
         else:
             rootdirs.append(root)
             root = os.path.dirname(root)  # up a level
 
     if verbose:
-        print("Tried directories %s but none started with prefix %s" %
-              (str(rootdirs), parentdir_prefix))
+        print(
+            "Tried directories %s but none started with prefix %s"
+            % (str(rootdirs), parentdir_prefix)
+        )
     raise NotThisMethod("rootdir doesn't start with parentdir_prefix")
 
 
@@ -181,7 +190,7 @@ def git_versions_from_keywords(keywords, tag_prefix, verbose):
     # starting in git-1.8.3, tags are listed as "tag: foo-1.0" instead of
     # just "foo-1.0". If we see a "tag: " prefix, prefer those.
     TAG = "tag: "
-    tags = set([r[len(TAG):] for r in refs if r.startswith(TAG)])
+    tags = set([r[len(TAG) :] for r in refs if r.startswith(TAG)])
     if not tags:
         # Either we're using git < 1.8.3, or there really are no tags. We use
         # a heuristic: assume all version tags have a digit. The old git %d
@@ -190,27 +199,34 @@ def git_versions_from_keywords(keywords, tag_prefix, verbose):
         # between branches and tags. By ignoring refnames without digits, we
         # filter out many common branch names like "release" and
         # "stabilization", as well as "HEAD" and "master".
-        tags = set([r for r in refs if re.search(r'\d', r)])
+        tags = set([r for r in refs if re.search(r"\d", r)])
         if verbose:
             print("discarding '%s', no digits" % ",".join(refs - tags))
     if verbose:
         print("likely tags: %s" % ",".join(sorted(tags)))
     for ref in sorted(tags):
         # sorting will prefer e.g. "2.0" over "2.0rc1"
         if ref.startswith(tag_prefix):
-            r = ref[len(tag_prefix):]
+            r = ref[len(tag_prefix) :]
             if verbose:
                 print("picking %s" % r)
-            return {"version": r,
-                    "full-revisionid": keywords["full"].strip(),
-                    "dirty": False, "error": None,
-                    "date": date}
+            return {
+                "version": r,
+                "full-revisionid": keywords["full"].strip(),
+                "dirty": False,
+                "error": None,
+                "date": date,
+            }
     # no suitable tags, so version is "0+unknown", but full hex is still there
     if verbose:
         print("no suitable tags, using unknown + full revision id")
-    return {"version": "0+unknown",
-            "full-revisionid": keywords["full"].strip(),
-            "dirty": False, "error": "no suitable tags", "date": None}
+    return {
+        "version": "0+unknown",
+        "full-revisionid": keywords["full"].strip(),
+        "dirty": False,
+        "error": "no suitable tags",
+        "date": None,
+    }
 
 
 @register_vcs_handler("git", "pieces_from_vcs")
@@ -225,19 +241,27 @@ def git_pieces_from_vcs(tag_prefix, root, verbose, run_command=run_command):
     if sys.platform == "win32":
         GITS = ["git.cmd", "git.exe"]
 
-    out, rc = run_command(GITS, ["rev-parse", "--git-dir"], cwd=root,
-                          hide_stderr=True)
+    out, rc = run_command(GITS, ["rev-parse", "--git-dir"], cwd=root, hide_stderr=True)
     if rc != 0:
         if verbose:
             print("Directory %s not under git control" % root)
         raise NotThisMethod("'git rev-parse --git-dir' returned error")
 
     # if there is a tag matching tag_prefix, this yields TAG-NUM-gHEX[-dirty]
     # if there isn't one, this yields HEX[-dirty] (no NUM)
-    describe_out, rc = run_command(GITS, ["describe", "--tags", "--dirty",
-                                          "--always", "--long",
-                                          "--match", "%s*" % tag_prefix],
-                                   cwd=root)
+    describe_out, rc = run_command(
+        GITS,
+        [
+            "describe",
+            "--tags",
+            "--dirty",
+            "--always",
+            "--long",
+            "--match",
+            "%s*" % tag_prefix,
+        ],
+        cwd=root,
+    )
     # --long was added in git-1.5.5
     if describe_out is None:
         raise NotThisMethod("'git describe' failed")
@@ -260,17 +284,16 @@ def git_pieces_from_vcs(tag_prefix, root, verbose, run_command=run_command):
     dirty = git_describe.endswith("-dirty")
     pieces["dirty"] = dirty
     if dirty:
-        git_describe = git_describe[:git_describe.rindex("-dirty")]
+        git_describe = git_describe[: git_describe.rindex("-dirty")]
 
     # now we have TAG-NUM-gHEX or HEX
 
     if "-" in git_describe:
         # TAG-NUM-gHEX
-        mo = re.search(r'^(.+)-(\d+)-g([0-9a-f]+)$', git_describe)
+        mo = re.search(r"^(.+)-(\d+)-g([0-9a-f]+)$", git_describe)
         if not mo:
             # unparseable. Maybe git-describe is misbehaving?
-            pieces["error"] = ("unable to parse git-describe output: '%s'"
-                               % describe_out)
+            pieces["error"] = "unable to parse git-describe output: '%s'" % describe_out
             return pieces
 
         # tag
@@ -279,10 +302,12 @@ def git_pieces_from_vcs(tag_prefix, root, verbose, run_command=run_command):
             if verbose:
                 fmt = "tag '%s' doesn't start with prefix '%s'"
                 print(fmt % (full_tag, tag_prefix))
-            pieces["error"] = ("tag '%s' doesn't start with prefix '%s'"
-                               % (full_tag, tag_prefix))
+            pieces["error"] = "tag '%s' doesn't start with prefix '%s'" % (
+                full_tag,
+                tag_prefix,
+            )
             return pieces
-        pieces["closest-tag"] = full_tag[len(tag_prefix):]
+        pieces["closest-tag"] = full_tag[len(tag_prefix) :]
 
         # distance: number of commits since tag
         pieces["distance"] = int(mo.group(2))
@@ -293,13 +318,13 @@ def git_pieces_from_vcs(tag_prefix, root, verbose, run_command=run_command):
     else:
         # HEX: no tags
         pieces["closest-tag"] = None
-        count_out, rc = run_command(GITS, ["rev-list", "HEAD", "--count"],
-                                    cwd=root)
+        count_out, rc = run_command(GITS, ["rev-list", "HEAD", "--count"], cwd=root)
         pieces["distance"] = int(count_out)  # total number of commits
 
     # commit date: see ISO-8601 comment in git_versions_from_keywords()
-    date = run_command(GITS, ["show", "-s", "--format=%ci", "HEAD"],
-                       cwd=root)[0].strip()
+    date = run_command(GITS, ["show", "-s", "--format=%ci", "HEAD"], cwd=root)[
+        0
+    ].strip()
     pieces["date"] = date.strip().replace(" ", "T", 1).replace(" ", "", 1)
 
     return pieces
@@ -330,8 +355,7 @@ def render_pep440(pieces):
                 rendered += ".dirty"
     else:
         # exception #1
-        rendered = "0+untagged.%d.g%s" % (pieces["distance"],
-                                          pieces["short"])
+        rendered = "0+untagged.%d.g%s" % (pieces["distance"], pieces["short"])
         if pieces["dirty"]:
             rendered += ".dirty"
     return rendered
@@ -445,11 +469,13 @@ def render_git_describe_long(pieces):
 def render(pieces, style):
     """Render the given version pieces into the requested style."""
     if pieces["error"]:
-        return {"version": "unknown",
-                "full-revisionid": pieces.get("long"),
-                "dirty": None,
-                "error": pieces["error"],
-                "date": None}
+        return {
+            "version": "unknown",
+            "full-revisionid": pieces.get("long"),
+            "dirty": None,
+            "error": pieces["error"],
+            "date": None,
+        }
 
     if not style or style == "default":
         style = "pep440"  # the default
@@ -469,9 +495,13 @@ def render(pieces, style):
     else:
         raise ValueError("unknown style '%s'" % style)
 
-    return {"version": rendered, "full-revisionid": pieces["long"],
-            "dirty": pieces["dirty"], "error": None,
-            "date": pieces.get("date")}
+    return {
+        "version": rendered,
+        "full-revisionid": pieces["long"],
+        "dirty": pieces["dirty"],
+        "error": None,
+        "date": pieces.get("date"),
+    }
 
 
 def get_versions():
@@ -485,8 +515,7 @@ def get_versions():
     verbose = cfg.verbose
 
     try:
-        return git_versions_from_keywords(get_keywords(), cfg.tag_prefix,
-                                          verbose)
+        return git_versions_from_keywords(get_keywords(), cfg.tag_prefix, verbose)
     except NotThisMethod:
         pass
 
@@ -495,13 +524,16 @@ def get_versions():
         # versionfile_source is the relative path from the top of the source
         # tree (where the .git directory might live) to this file. Invert
         # this to find the root from __file__.
-        for i in cfg.versionfile_source.split('/'):
+        for i in cfg.versionfile_source.split("/"):
             root = os.path.dirname(root)
     except NameError:
-        return {"version": "0+unknown", "full-revisionid": None,
-                "dirty": None,
-                "error": "unable to find root of source tree",
-                "date": None}
+        return {
+            "version": "0+unknown",
+            "full-revisionid": None,
+            "dirty": None,
+            "error": "unable to find root of source tree",
+            "date": None,
+        }
 
     try:
         pieces = git_pieces_from_vcs(cfg.tag_prefix, root, verbose)
@@ -515,6 +547,10 @@ def get_versions():
     except NotThisMethod:
         pass
 
-    return {"version": "0+unknown", "full-revisionid": None,
-            "dirty": None,
-            "error": "unable to compute version", "date": None}
+    return {
+        "version": "0+unknown",
+        "full-revisionid": None,
+        "dirty": None,
+        "error": "unable to compute version",
+        "date": None,
+    }