CSVfailid

CSV failid, short for comma-separated values failid, are a simple plain-text format for representing tabular data. Each line represents a record, and each field within the line is separated by a delimiter, most commonly a comma. In many European locales a semicolon is used instead of a comma to suit the decimal separator. A header row naming the fields is common but not required.

Fields containing the delimiter, a quotation mark, or line breaks are typically enclosed in double quotes. Inside a quoted field, a double quote is escaped by doubling it. Line endings may be CRLF or LF, depending on platform. Encoding is usually UTF-8, but legacy files may use other encodings or include a byte order mark (BOM).

RFC 4180 provides a widely cited specification outlining conventions such as the use of CRLF line breaks, double-quote escaping, and consistent field counts, but actual implementations vary.

Common issues include inconsistent delimiters, mismatched quoting, embedded newlines, missing or extra fields on records, and nonuniform use of a header row. These problems can complicate parsing and data imports across software.

CSV is broadly supported by most data tools and programming languages. Examples of tooling include Python's csv module, pandas, R's read.csv, and spreadsheet applications such as Microsoft Excel and LibreOffice Calc. Advantages of CSV include simplicity, human readability, and easy generation; limitations include lack of explicit data types, schemas, or metadata, and potential ambiguity when fields contain delimiters or line breaks without proper escaping.