Fix some python linter errors

tools/auto_analyse_raw_data.py

@@ -303,9 +303,10 @@ def convert_rawdata(data_str):
   for timing in [x.strip() for x in data_str.split(',')]:
     try:
       results.append(int(timing))
-    except ValueError:
+    except ValueError as non_numeric:
       raise ValueError(
-          "Raw Data contains a non-numeric value of '%s'." % timing)
+          "Raw Data contains a non-numeric value of '%s'." %
+          timing) from non_numeric
   return results
 
 

tools/scrape_supported_devices.py

@@ -93,7 +93,7 @@ def getallacs():
     match = IRSEND_FN_RE.match(path.name)
     if match:
       rawmodels = getenums(path)
-      for acprotocol in rawmodels:
+      for acprotocol in rawmodels.keys():
         models = set()
         for model in rawmodels[acprotocol]:
           model = model.upper()