Python实现Linux环境下的ls命

import os
import re
import sys
path = os.getcwd()
substr = raw_input('The sub-string of the file (Support for Regular Expression): ')
reg = r'' + substr
count = 0
totalSize = 0
fileList = os.listdir(path)

def getFileSize(filePath):
	return os.path.getsize(filePath)

def humanReadFileSize(fileByte):
	# fileByte = str(getFileSize(filePath))
	if fileByte == 0:
		return ''
	elif fileByte < 1024:
		# B
		fileSize = str(fileByte) + ' B'
	elif fileByte < 1024*1024:
		# KB
		fileSize = str(fileByte/1024.0) + ' KB'
	elif fileByte < 1024*1024*1024:
		# MB
		fileSize = str(fileByte/1024.0/1024.0) + ' MB'
	else:
		# GB
		fileSize = str(fileByte/1024.0/1024.0/1024.0) + ' GB'
	return fileSize

for fileName in fileList:
	if re.match(reg, fileName):
		count = count+1
		filePath = os.path.join(path, fileName)
		fileSize = getFileSize(filePath)

		totalSize = totalSize+fileSize
		print '\t', count, ' - ', humanReadFileSize(fileSize).ljust(30, ' '), fileName
		print '-'*160
		if len(sys.argv)!=1:
			if sys.argv[1] == 'remove':
				os.remove(filePath)

print '\n\t\t%d file(s) in total, total size: %s' % (count, humanReadFileSize(totalSize))