it’s a windows/linux thing for sure.
python 2/3 tries to adhere to standard fopen() semantics. documentation for both python 2.7 and 3.9 clearly states that text mode is the default (when neither t nor b is specified), and text mode may touch newlines.
this newline conversion is only done because windows uses CRLF and historically didn’t understand anything else… but these days it – and most programs running on windows! --have no problems with that.