Minor Python tidies in apply-fixit-edits.py

* Use `collections.defaultdict` instead of a regular dict, so we don't have to initialise the dict keys
* Add edits to `edits_per_file` directly, rather than via an intermediate set
* Use tuple unpacking in the final loop so it's easier to see the similarity between the unpacked variables and the tuple added on line 47

Author: alexwlchan

utils/apply-fixit-edits.py

@@ -12,6 +12,7 @@
 from __future__ import print_function
 
 import argparse
+import collections
 import json
 import os
 import sys
@@ -31,7 +32,7 @@ def apply_edits(path):
         print("No remap files found")
         return 1
 
-    edits_set = set()
+    edits_per_file = collections.defaultdict(list)
     for remap_file in remap_files:
         with open(remap_file) as f:
             json_data = f.read()
@@ -43,24 +44,15 @@ def apply_edits(path):
             offset = ed["offset"]
             length = ed.get("remove", 0)
             text = ed.get("text", "")
-            edits_set.add((fname, offset, length, text))
-
-    edits_per_file = {}
-    for ed in edits_set:
-        fname = ed[0]
-        if fname not in edits_per_file:
-            edits_per_file[fname] = []
-        edits_per_file[fname].append((ed[1], ed[2], ed[3]))
+            edits_per_file[fname].append((offset, length, text))
 
     for fname, edits in edits_per_file.iteritems():
         print('Updating', fname)
         edits.sort(reverse=True)
         with open(fname) as f:
             file_data = f.read()
         for ed in edits:
-            offset = ed[0]
-            length = ed[1]
-            text = ed[2]
+            offset, length, text = ed
             file_data = file_data[:offset] + str(text) + \
                 file_data[offset + length:]
         with open(fname, 'w') as f: