from sys import *

class pgm:
	def __init__(self, magic_num='',width=0,height=0,max_grey=0,fname='',data=[]):
		#initialize a blank pgm.
		self.width=width
		self.height=height
		self.max_grey=max_grey
		self.data=data
		self.magic_num=magic_num
		self.tdata = []
	
	def open_pgm(self,path):
		
		#get all the lines of the file
		IFile = open(path,"rb")
		print "getting data"
		try:
			self.magic_num = IFile.readline().strip()
			tmp_holder = IFile.readline().strip().split()
			self.width = int(tmp_holder[0])
			self.height = int(tmp_holder[1])
			self.max_grey = int(IFile.readline().strip())
		except:
			print "invalid header, expected:"
			print "P2\nxxx xxx\n255\n"
			print "found:"
			print str(self.magic_num) + "\n" + str(self.width) + " " +str(self.height)
			print str(self.max_grey)
					
		for line in IFile:
			tmp_dat = IFile.readline().strip().split()
			print tmp_dat
			try:
				self.data.append(tmp_dat)
			except:
				print "'data.append(tmp_dat)' failed"

		
	def toString(self):
		print self.magic_num
		print str(self.width) + " " + str(self.height)
		print self.max_grey
		print ""
		#print self.data
	
	def toFile(self, path):
		OFile = open(path,"w")
		OFile.write(self.magic_num + "\n")
		OFile.write(str(self.width) + " " + str(self.height) + "\n")
		OFile.write(str(self.max_grey) + "\n")

		for i in self.data:
			for j in i:
				OFile.write(j + " ")
			OFile.write("\n")
		OFile.close()


#EOF


user@host$head $INPUTFILE
P2
300 202
255
 104 106 107 107 106 106 107 108 107 107 107 107
 108 108 108 108 109 109 109 109 109 109 111 112
 110 111 111 111 110 110 111 112 112 112 112 112
 113 113 113 113 114 115 115 115 116 116 115 115
 114 116 116 115 115 116 116 115 117 117 117 117
 116 116 117 117 118 118 118 118 118 119 119 119
 119 119 119 120 120 121 120 120 120 121 122 122

user@host$head $OUTPUTFILE
P2
300 202
255
133 134
134 134 135 134 133 133 133 134 135 134 134 134
134 133 133 133 134 134 134 134 134 133 133 133
134 134 134 135 135 134 134 134 134 135 135 134
134 133 133 134 134 134 133 133 133 134 134 134
134 133 133 133 133 133 133 133 133 132 133 133
132 133 135 135 134 134 134 134 134 134 134 134