CSV格式化（d3.csv）

• d3.csv - request a comma-separated values (CSV) file.
• d3.csv.parse - parse a CSV string into objects using the header row.
• d3.csv.parseRows - parse a CSV string into tuples, ignoring the header row.
• d3.csv.format - format an array of objects into a CSV string.
• d3.csv.formatRows - format an array of tuples into a CSV string.
• d3.tsv - request a tab-separated values (TSV) file.
• d3.tsv.parse - parse a TSV string into objects using the header row.
• d3.tsv.parseRows - parse a TSV string into tuples, ignoring the header row.
• d3.tsv.format - format an array of objects into a TSV string.
• d3.tsv.formatRows - format an array of tuples into a TSV string.
• d3.dsv - create a parser/formatter for the specified delimiter and mime type.