[chirp_devel] [PATCH 01/22] Allow cpep8.py script to make exceptions (#2355)

[Zach Welch]

# HG changeset patch
# User Zach Welch <zach at mandolincreekfarm.com>
# Fake Node ID 13e436ae19e0b0ac7a0a9646247e4306216f4707

Allow cpep8.py script to make exceptions (#2355)

This patch enhances the cpep8.py script with the ability to ignore a
list of style rules on per-file basis.  There are cases where it may be
too disruptive to eliminate all style issues, so this mechanism allows
the style checker to enforce the remainder of the style rules.  The new
--strict option will cause the script to ignore the exception list.

As a bonus, this change improves interactivity, so --verbose will cause
the name of the file to be printed as it is checked (rather than
printing one long list before it started).  The downside: the pep8
module catches KeyboardInterrpt, so it's hard impossible to stop once it
gets started.

diff --git a/tools/cpep8.exceptions b/tools/cpep8.exceptions
new file mode 100644
index 0000000..6fcce63
--- /dev/null
+++ b/tools/cpep8.exceptions
@@ -0,0 +1,4 @@
+# This file contains a list of per-file exceptions to the pep8 style rules
+# Each line must contain the file name, a tab, and a comma-separated list
+# of style rules to ignore in that file.  This mechanism should be used
+# sparingly and as a measure of last resort.
diff --git a/tools/cpep8.py b/tools/cpep8.py
index db33ab1..fb1ff48 100755
--- a/tools/cpep8.py
+++ b/tools/cpep8.py
@@ -30,6 +30,8 @@ parser.add_argument("-d", "--dir", action="store", default=".",
                     help="Root directory of source tree")
 parser.add_argument("-s", "--stats", action="store_true",
                     help="Only show statistics")
+parser.add_argument("--strict", action="store_true",
+                    help="Ignore listed exceptions")
 parser.add_argument("-S", "--scan", action="store_true",
                     help="Scan for additional files")
 parser.add_argument("-u", "--update", action="store_true",
@@ -52,6 +54,7 @@ def file_to_lines(name):
 scriptdir = os.path.dirname(sys.argv[0])
 manifest_filename = os.path.join(scriptdir, "cpep8.manifest")
 blacklist_filename = os.path.join(scriptdir, "cpep8.blacklist")
+exceptions_filename = os.path.join(scriptdir, "cpep8.exceptions")
 
 manifest = []
 if args.scan:
@@ -68,10 +71,28 @@ if args.scan:
 else:
     manifest += file_to_lines(manifest_filename)
 
+
+# unless we are being --strict, load per-file style exceptions
+exceptions = {}
+if not args.strict:
+    exception_lines = file_to_lines(exceptions_filename)
+    exception_lists = [x.split('\t')
+                       for x in exception_lines if not x.startswith('#')]
+    for filename, codes in exception_lists:
+        exceptions[filename] = codes
+
+
+def get_exceptions(f):
+    try:
+        ignore = exceptions[f]
+    except KeyError:
+        ignore = None
+    return ignore
+
 if args.update:
     bad = []
     for f in manifest:
-        checker = pep8.StyleGuide(quiet=True)
+        checker = pep8.StyleGuide(quiet=True, ignore=get_exceptions(f))
         results = checker.check_files([f])
         if results.total_errors:
             bad.append(f)
@@ -100,12 +121,15 @@ for f in manifest:
         check_list.append(f)
 check_list = sorted(check_list)
 
-if args.verbose:
-    print "Checking the following files:\n", "\n".join(check_list)
+total_errors = 0
+for f in check_list:
+    if args.verbose:
+        print "Checking %s" % f
 
-checker = pep8.StyleGuide(quiet=args.stats)
-results = checker.check_files(check_list)
-if args.stats:
-    results.print_statistics()
+    checker = pep8.Checker(f, quiet=args.stats, ignore=get_exceptions(f))
+    results = checker.check_all()
+    if args.stats:
+        checker.report.print_statistics()
+    total_errors += results
 
-sys.exit(results.total_errors and 1 or 0)
+sys.exit(total_errors and 1 or 0)