I am a data scientist and regularly refer to various file types when writing to others.
My question is this: what is the correct and/or proper way to refer to a file type and which of the following sentences is correct?
"Here is the .csv you asked for."
"Here is the CSV you asked for."
Note: .csv/CSV is used as an example only; this could be any file type (i.e. .pdf/PDF, .xlsx/XLSX). I have also excluded the word "file" from the sentence simply because it isn't the focus of my question. My question is asking how best to represent file types in writing. In this context, the other words in the sentence are irrelevant.