Linux Login crack - Printable Version

Code:
#!/usr/bin/python

 import sys
 import crypt
 import os
 import threading
 import argparse
 flag=0
 #console color
 W  = '\033[0m'  # white (normal)
 R  = '\033[31m' # red
 G  = '\033[32m' # green
 O  = '\033[33m' # orange
 B  = '\033[34m' # blue
 P  = '\033[35m' # purple

 if os.getuid() != 0:
         print R+' [!]'+O+' ERROR:'+G+' logincrack.py'+O+' must be run as '+R+'root'+W
         print R+' [!]'+O+' login as root ('+W+'su root'+O+') or try '+W+'sudo ./logincrack.py'+W
         exit(1)
       

 def searching(y,salt,hash):
     if crypt.crypt(y,salt)==hash:        
         print O + "\n[+] " + B + y + "\n" + W
 class crack:
     """ This will extract all the user and the hash from the givne input
 file """
     def __init__(self,file,w):
         self.file=file
         self.user_hash={}
         self.f=open(file,'r')
         self.dict=open(w,'r')
     def user(self,u):
         self.u=u
         for x in self.f:
             y=x.split(":")
             if y[0]==u:
                 self.user_hash[u]=y[1]
     def cracking(self):
         if self.user_hash:
             print "user " + R + self.u + W + " found"
             print P + "Now Cracking " + R + self.u + P +" , be relax" + W
             print "\nNumber of password tried: "
             for x in self.user_hash.keys():
                 hash=self.user_hash[x].split("$")[1:]
                 count=1
                 for y in self.dict:
                     salt="$"+hash[0]+"$"+hash[1]+"$"
                     t=threading.Thread(target=searching,args=(y.strip('\n'),salt,self.user_hash[x]))
                     t.start()
                     sys.stdout.write("\r" + R + str(count)+W)
                     count=count+1
         else:
             print R + '[!]'+ O+ " user specified " + B + self.u +R +" not found in file " + P + self.file  
             exit

 def option():
     parser=argparse.ArgumentParser(description="Login hashcracker")
     parser.add_argument('-u',metavar='user_name',help='username for which the hash will be cracked')
     parser.add_argument('-d',metavar='dictionary_file',help='file for dictionary attack')
     parser.add_argument('hash_file',metavar='hash_file',help='the file that contains username and the hash')
     args=parser.parse_args()
     c=crack(args.hash_file,args.d)
     c.user(args.u)
     c.cracking()

 if __name__ == '__main__':
     option()