Purpose: don't remove cython output.
diff --git a/setup.py b/setup.py
index 31048b3..a7a5120 100755
--- a/setup.py
+++ b/setup.py
@@ -66,6 +66,7 @@ def clean(path):
         name = name.replace('.', '/')
         for ext in ['.so', '.html', '.cpp', '.c']:
             file_path = os.path.join(path, name + ext)
+            if file_path.endswith('mrmr.cpp'): continue
             if os.path.exists(file_path):
                 os.unlink(file_path)