import test_support,unittest import codecs import StringIO class UTF16Test(unittest.TestCase): spamle = '\xff\xfes\x00p\x00a\x00m\x00s\x00p\x00a\x00m\x00' spambe = '\xfe\xff\x00s\x00p\x00a\x00m\x00s\x00p\x00a\x00m' def test_only_one_bom(self): _,_,reader,writer = codecs.lookup("utf-16") # encode some stream s = StringIO.StringIO() f = writer(s) f.write(u"spam") f.write(u"spam") d = s.getvalue() # check whether there is exactly one BOM in it self.assert_(d == self.spamle or d == self.spambe) # try to read it back s = StringIO.StringIO(d) f = reader(s) self.assertEquals(f.read(), u"spamspam") test_support.run_unittest(UTF16Test)