#!/usr/bin/env python## A format checker for LIBSVM### Copyright (c) 2007, Rong-En Fan## All rights reserved.## This program is distributed under the same license of the LIBSVM package.# from sys import argv, exitimport os.pathdef err(line_no, msg):	print "line %d: %s" % (line_no, msg)# works like float() but does not accept nan and infdef my_float(x):	if x.lower().find("nan") != -1 or x.lower().find("inf") != -1:		raise ValueError	return float(x)def main():	if len(argv) != 2:		print "Usage: %s dataset" % (argv[0])		exit(1)	dataset = argv[1]	if not os.path.exists(dataset):		print "dataset %s not found" % (dataset)		exit(1)	line_no = 1	error_line_count = 0	for line in open(dataset, 'r'):		line_error = False		# each line must end with a newline character		if line[-1] != '\n':			err(line_no, "missing a newline character in the end")			line_error = True		nodes = line.split()		# check label		try:			label = nodes.pop(0)						if label.find(',') != -1:				# multi-label format				try:					for l in label.split(','):						label = my_float(label)				except:					err(line_no, "label %s is not a valid multi-label form" % label)					line_error = True			else:				try:					label = my_float(label)				except:					err(line_no, "label %s is not a number" % label)					line_error = True		except:			err(line_no, "missing label, perhaps an empty line?")			line_error = True		# check features		prev_index = -1		for i in range(len(nodes)):			try:				(index, value) =  nodes[i].split(':')				index = int(index)				value = my_float(value)				# precomputed kernel's index starts from 0 and LIBSVM				# checks it. Hence, don't treat index 0 as an error.				if index < 0:					err(line_no, "feature index must be positive; wrong feature %s" % nodes[i])					line_error = True				elif index < prev_index:					err(line_no, "feature indices must be in an ascending order, previous/current features %s %s" % (nodes[i-1], nodes[i]))					line_error = True				prev_index = index			except:				err(line_no, "feature '%s' not an <index>:<value> pair, <index> integer, <value> real number " % nodes[i])				line_error = True		line_no += 1		if line_error:			error_line_count += 1		if error_line_count > 0:		print "Found %d lines with error." % (error_line_count)	else:		print "No error."main()