fix Python 3 issue

Author: kilink

src/ghdiff.py

@@ -128,14 +128,14 @@ def main(args=None, stdout=sys.stdout):
         sys.exit(-1)
 
     def read_file(filename):
-        with open(filename) as f:
+        with open(filename, "rb") as f:
             text = f.read()
         codepage = chardet.detect(text)['encoding']
         return text.decode(codepage).splitlines()
 
     a = read_file(args[0])
     b = read_file(args[1])
-    six.print_(diff(a, b, css=options.css).encode('utf-8'), file=stdout)
+    stdout.write(diff(a, b, css=options.css).encode("utf-8"))
 
 if __name__ == "__main__":
     main(sys.argv[1:])

src/tests.py

@@ -33,8 +33,8 @@ def test_script(self):
         out = io.BytesIO()
         ghdiff.main([f1, f2], stdout=out)
         output = out.getvalue()
-        self.assertTrue("-foobar" in output)
-        self.assertTrue('+foobar<span class="highlight">baz</span>' in output)
+        self.assertTrue(b"-foobar" in output)
+        self.assertTrue(b'+foobar<span class="highlight">baz</span>' in output)
 
     def test_no_css_option(self):
         """Simple test for --no-css option"""
@@ -43,7 +43,7 @@ def test_no_css_option(self):
         out = io.BytesIO()
         ghdiff.main([f1, f2, "--no-css"], stdout=out)
         output = out.getvalue()
-        self.assertFalse("<style" in output)
+        self.assertFalse(b"<style" in output)
 
 
 def test_suite():