# CSV I/O

import csv

import StringIO

def reader_and_header(stream):

    '''Automatically detects the dialect based on the header line

    @return tuple (reader, header)'''

    header_line = stream.readline()

    dialect = csv.Sniffer().sniff(header_line)

    header = csv.reader(StringIO.StringIO(header_line), dialect).next()

    return (csv.reader(stream, dialect), header)