whitespace in expected output. Stop that.
Some people use different formatting conventions, which makes
untokenize a little trickier. Note that this test involves trailing
-whitespace after the colon. You can't see it, but it's there!
+whitespace after the colon. Note that we use hex escapes to make the
+two trailing blanks apparent in the expected output.
>>> roundtrip("if x == 1 : \\n"
... " print x\\n")
-if x == 1 :
+if x == 1 :\x20\x20
print x
Comments need to go in the right place.