scripts: Adopted Attr rework in plot.py/plotmpl.py

Unifying these complicated attr-assigning flags across all the scripts
is the main benefit of the new internal Attr system.

The only tricky bit is we need to somehow keep track of all input fields
in case % modifiers reference fields, when we could previously discard
non-data fields.

Tricky but doable.

Updated flags:

- -L/--label -> -L/--add-label
- --colors -> -C/--add-color
- --formats -> -F/--add-format
- --chars -> -*/--add-char/--chars
- --line-chars -> -_/--add-line-char/--line-chars

I've also tweaked Attr to accept glob matches when figuring out group
assignments. This is useful for matching slightly different, but
similarly named results in our benchmark scripts.

There's probably a clever way to do this by injecting new by fields with
csv.py, but just adding globbing is simpler and makes attr assignment
even more flexible.

scripts/treemap.py

@@ -11,6 +11,7 @@ if __name__ == "__main__":
 import bisect
 import collections as co
 import csv
+import fnmatch
 import itertools as it
 import math as mt
 import re
@@ -163,7 +164,7 @@ class Attr:
         if (defaults is not None
                 and not any(
                     not isinstance(attr, tuple)
-                        or attr[0] in {None, (), ('',)}
+                        or attr[0] in {None, (), ('*',)}
                     for attr in (attrs or []))):
             attrs = defaults + (attrs or [])
 
@@ -173,7 +174,7 @@ class Attr:
         for attr in (attrs or []):
             if not isinstance(attr, tuple):
                 attr = ((), attr)
-            elif attr[0] in {None, (), ('',)}:
+            elif attr[0] in {None, (), ('*',)}:
                 attr = ((), attr[1])
 
             self.attrs.append(attr)
@@ -206,7 +207,7 @@ class Attr:
         for ks, vs in self.keyed.items():
             prefix = []
             for j, k in enumerate(ks):
-                if j < len(key) and (not k or key[j] == k):
+                if j < len(key) and fnmatch.fnmatchcase(key[j], k):
                     prefix.append(k)
                 else:
                     prefix = None
@@ -225,6 +226,33 @@ class Attr:
     def __contains__(self, key):
         return self.__getitem__(key) is not None
 
+    # a key function for sorting by key order
+    def key(self, key):
+        # allow key to be a tuple to make sorting dicts easier
+        if (isinstance(key, tuple)
+                and len(key) >= 1
+                and isinstance(key[0], tuple)):
+            key = key[0]
+
+        best = None
+        for i, ks in enumerate(self.keyed.keys()):
+            prefix = []
+            for j, k in enumerate(ks):
+                if j < len(key) and (not k or key[j] == k):
+                    prefix.append(k)
+                else:
+                    prefix = None
+                    break
+
+            if prefix is not None and (
+                    best is None or len(prefix) >= len(best[0])):
+                best = (prefix, i)
+
+        if best is not None:
+            return best[1]
+
+        return len(self.keyed)
+
 # parse %-escaped strings
 def punescape(s, attrs=None):
     if attrs is None:
@@ -673,9 +701,9 @@ def main(csv_paths, *,
         by=None,
         fields=None,
         defines=[],
-        labels=None,
-        chars=None,
-        colors=None,
+        labels=[],
+        chars=[],
+        colors=[],
         color=False,
         dots=False,
         braille=False,
@@ -698,7 +726,7 @@ def main(csv_paths, *,
 
     # what chars/colors/labels to use?
     chars_ = []
-    for char in (chars or []):
+    for char in chars:
         if isinstance(char, tuple):
             chars_.extend((char[0], c) for c in char[1])
         else:
@@ -1004,7 +1032,7 @@ if __name__ == "__main__":
                 "where a group is the comma-separated 'by' fields. Accepts %% "
                 "modifiers.")
     parser.add_argument(
-            '-.', '--add-char', '--chars',
+            '-*', '--add-char', '--chars',
             dest='chars',
             action='append',
             type=lambda x: (