Hi Sai,

I assume that the problem comes not from the PySpark, but from Excel.

I tried to reproduce the error and didn't find the way - that a good thing, right ? Please try the following : 

df.write.format("csv").save("/Volumes/<my_catalog_name>/<my_schema_name>/<my_volume_name>/<file_name>")

(how to create a Volume ; Volumes have a lot of value, but if you prefer to use a path in your object storage it's also ok)