Enforce Python 2/3 consistent JSON separators

Author: jakirkham

zarr/attrs.py

@@ -24,7 +24,7 @@ def __getitem__(self, item):
         return self.asdict()[item]
 
     def _put(self, d):
-        s = json.dumps(d, indent=4, sort_keys=True, ensure_ascii=True)
+        s = json.dumps(d, indent=4, sort_keys=True, ensure_ascii=True, separators=(',', ': '))
         self.store[self.key] = s.encode('ascii')
 
     def _write_op(self, f, *args, **kwargs):

zarr/meta.py

@@ -64,7 +64,7 @@ def encode_array_metadata(meta):
         order=meta['order'],
         filters=meta['filters'],
     )
-    s = json.dumps(meta, indent=4, sort_keys=True, ensure_ascii=True)
+    s = json.dumps(meta, indent=4, sort_keys=True, ensure_ascii=True, separators=(',', ': '))
     b = s.encode('ascii')
     return b