What is the difference between `sep` and `delimiter` attributes in pandas.read_csv() method?

Question

What is the difference between sep and delimiter attributes in pandas.read_csv() method?

Also what is the situation when I would choose one over the other?

In documentation I read something about Python builtin sniffer tool, also in delimiter, it says alternative argument name for sep, then why cant we have only one attribute?

Answer 1

Confirmation that they are the same thing can be found in the source code:

# Alias sep -> delimiter.
if delimiter is None:
    delimiter = sep

I agree with the other answer that it is best to stick to sep. It seems to be more commonly used, and it is more consistent with other functions such as to_csv, which does not accept delimiter, only sep.

Answer 2

They're the same thing. See here.

I assume one is for backwards compatibility. I'd just use sep, it's what I see the most.