import csv

sniff_range = 4096
delimiters = ';\t,'

infile_name = 'blabla.csv'

sniffer = csv.Sniffer()

print 'Reading file: %s' % infile_name

with open(infile_name, 'r') as infile:
    # Determine dialect
    dialect = sniffer.sniff(
        infile.read(sniff_range), delimiters=delimiters
    )
    infile.seek(0)

    # Sniff for header
    has_header = sniffer.has_header(infile.read(sniff_range))
    infile.seek(0)

    reader = csv.reader(infile, dialect)