def csv2tsv(filestr, outstr = None):
	if outstr == None:
		outstr = filestr
	ifile = open(filestr)
	import numpy as np
	data = np.genfromtxt(ifile, delimiter=',', dtype=None, names=None)
	ofile = open(outstr, 'w+')
	for row in data:
		ofile.write('\t'.join([str(x) for x in row])+'\n')
	ofile.close()