added hex methods

src/bits.py

@@ -921,6 +921,12 @@ class Bits:
             ret.append(Bit(b))
         return ret
 
+    def hex(self):
+        """
+        Return the hex-string representation of self
+        """
+        return bytes(self).hex()
+
 
 class Bytes:
     """
@@ -1125,6 +1131,15 @@ class Bytes:
             chop += 1
         return ret + bin(i)[chop:]
 
+    def hex(self, sep=None, bytes_per_sep=1):
+        """
+        Return the hex-string representation of self
+        """
+        if sep is None or bytes_per_sep is None or bytes_per_sep == 0:
+            return bytes(self).hex()
+        else:
+            return bytes(self).hex(sep=sep, bytes_per_sep=bytes_per_sep)
+
     @property
     def bytes(self):
         return bytes(self)