fix compression_opts in xdmf
@@ -325,7 +325,7 @@ class XdmfWriter:
self.data_format = data_format
self.data_counter = 0
self.compression = compression
- self.compression_opts = compression_opts
+ self.compression_opts = None if compression is None else compression_opts
if data_format == "HDF":
self.h5_filename = os.path.splitext(self.filename)[0] + ".h5"
