toPSV(...args) {
        return io.toPSV(this, ...args);
    }
Convert the DataFrame into a pipe separated values string. You can also save the file if you are using nodejs.
@param {Boolean} [header=true] Writing the header in the first line. If false, there will be no header.
@param {String} [path] The path to save the file. /!\ Works only on node.js, not into the browser.
@returns {String} The csv file in raw string.
@example
df.toPSV()
df.toPSV(true)
// From node.js only
df.toPSV(true, '/my/absolute/path/dataframe.csv')