diff --git a/can/dbc.py b/can/dbc.py
index cc149ec..cff65a1 100755
--- a/can/dbc.py
+++ b/can/dbc.py
@@ -98,11 +98,11 @@ class dbc():
         sgname = dat.group(2)
         defvals = dat.group(3)
 
-        defvals = defvals.replace("?",r"\?")  # escape sequence in C++
+        defvals = defvals.replace("?", r"\?")  # escape sequence in C++
         defvals = defvals.split('"')[:-1]
 
         # convert strings to UPPER_CASE_WITH_UNDERSCORES
-        defvals[1::2] = [d.strip().upper().replace(" ","_") for d in defvals[1::2]]
+        defvals[1::2] = [d.strip().upper().replace(" ", "_") for d in defvals[1::2]]
         defvals = '"'+"".join(str(i) for i in defvals)+'"'
 
         self.def_vals[ids].append((sgname, defvals))