If you need to read to import CSV from someone else, there are tons of ambiguities. Do you interpret an empty field as an empty string or a NULL? If you've trea

If you need to read to import CSV from someone else, there are tons of ambiguities. Do you interpret an empty field as an empty string or a NULL? If you've treated a column of unquoted digits as numbers so far, do you parse the first row with a non-number in that column as a NaN, NULL or string? If string, do you reinterpret all the previous column values as strings? Many people are not in the position to just return the file to the client/boss and tell them they have a "broken csv file". (They'll tell you they saved it in Excel and it reads back fine, so the problem must be on your end. E.g.: https://stackoverflow.com/questions/43273976/escaping-quotes-and-delimiters-in-csv-files-with-excel https://stackoverflow.com/questions/43273976/escaping-quotes...)