def METHOD_NAME(filename):
	mappedfile = open(filename,"r")
	map = {}
	for line in mappedfile:
	# might be two or three columns: accession \t taxonid \t strain
		fields = line.split("\t")
		if len(fields) >= 2:
			map[fields[0]] = fields[1].strip()
	mappedfile.close()
	print "Number accessions to start: ", len(map)
	return map