Use r-strings

And run black to keep things tidy

Closes #284.

mk-appendix.py

@@ -7,6 +7,7 @@
 IN_APPENDIX = None
 CURRENT = ""
 
+
 def print_syntax(val):
     vl = val.split("\n")
     last_empty = False
@@ -24,24 +25,24 @@ def print_syntax(val):
 
 for l in sys.stdin:
     if not IN_APPENDIX:
-        m = re.match('%%% (.*)$', l)
+        m = re.match(r"%%% (.*)$", l)
         if m is not None:
             IN_APPENDIX = m.group(1)
         else:
-            m = re.match('%%(#+|!) (.*)$', l)
+            m = re.match(r"%%(#+|!) (.*)$", l)
             if m is not None:
-                if m.group(1) != '!':
+                if m.group(1) != "!":
                     print("%s %s" % (m.group(1), m.group(2)))
                 print_syntax(APPENDICES[m.group(2)])
                 del APPENDICES[m.group(2)]
                 print()
             else:
-                print(l, end='')
+                print(l, end="")
     else:
         # Strip out everything marked as RESERVED
         if l.find("RESERVED") == -1:
-            print(l, end='')
-        m = re.match("\S", l)
+            print(l, end="")
+        m = re.match(r"\S", l)
         if m is None:
             CURRENT += l
         else: