DFReader_text: some arrays indexed by bytes instead of str

DFReader.py

@@ -192,7 +192,7 @@ def __getattr__(self, field):
         if self.fmt.msg_types[i] == str:
             v = null_term(v)
         if self.fmt.msg_mults[i] is not None and self._apply_multiplier:
-            v *= self.fmt.msg_mults[i]
+                v *= self.fmt.msg_mults[i]
         return v
 
     def __setattr__(self, field, value):
@@ -1086,7 +1086,7 @@ def make_format_msgbuf(self, fmt):
 def DFReader_is_text_log(filename):
     '''return True if a file appears to be a valid text log'''
     with open(filename, 'r') as f:
-        ret = (f.read(8000).find('FMT,') != -1)
+            ret = (f.read(8000).find('FMT,') != -1)
 
     return ret
 
@@ -1147,8 +1147,7 @@ def init_arrays(self, progress_callback=None):
 
         while ofs+16 < self.data_len:
             mtype = self.data_map[ofs:ofs+4]
-            if mtype[3] == b',':
-                mtype = mtype[0:3]
+            mtype = mtype.decode().rstrip(', ')
             if not mtype in self.offsets:
                 self.counts[mtype] = 0
                 self.offsets[mtype] = []