Be more explicit in byte_to_int errors

Author: tcalmant

javaobj/modifiedutf8.py

@@ -46,7 +46,11 @@ def byte_to_int(data):
         if isinstance(data, bytes):
             return data[0]
 
-        raise ValueError("Didn't get a byte as input")
+        raise ValueError(
+            "Expected byte or int as input, got: {0}".format(
+                type(data).__name__
+            )
+        )
 
 
 else:
@@ -65,7 +69,11 @@ def byte_to_int(data):
         if isinstance(data, str):
             return ord(data[0])
 
-        raise ValueError("Didn't get a byte as input")
+        raise ValueError(
+            "Expected byte or int as input, got: {0}".format(
+                type(data).__name__
+            )
+        )
 
 
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