cli: Don't encode/decode for stdin/stdout on Python 3

https://fedorahosted.org/freeipa/ticket/5638

Reviewed-By: Jan Cholasta <jcholast@redhat.com>

ipalib/cli.py

@@ -130,24 +130,31 @@ class textui(backend.Backend):
             return 'UTF-8'
         return stream.encoding
 
-    def decode(self, value):
-        """
-        Decode text from stdin.
-        """
-        if type(value) is bytes:
-            encoding = self.__get_encoding(sys.stdin)
-            return value.decode(encoding)
-        elif type(value) in (list, tuple):
-            return tuple(self.decode(v) for v in value)
-        return value
+    if six.PY2:
+        def decode(self, value):
+            """
+            Decode text from stdin.
+            """
+            if type(value) is bytes:
+                encoding = self.__get_encoding(sys.stdin)
+                return value.decode(encoding)
+            elif type(value) in (list, tuple):
+                return tuple(self.decode(v) for v in value)
+            return value
 
-    def encode(self, unicode_text):
-        """
-        Encode text for output to stdout.
-        """
-        assert type(unicode_text) is unicode
-        encoding = self.__get_encoding(sys.stdout)
-        return unicode_text.encode(encoding)
+        def encode(self, unicode_text):
+            """
+            Encode text for output to stdout.
+            """
+            assert type(unicode_text) is unicode
+            encoding = self.__get_encoding(sys.stdout)
+            return unicode_text.encode(encoding)
+    else:
+        def decode(self, value):
+            return value
+
+        def encode(self, value):
+            return value
 
     def choose_number(self, n, singular, plural=None):
         if n == 1 or plural is None: