Troubleshooting "TypeError: ord () expected string of length 1 but int found"

Question

ERROR : TypeError: ord() expected string of length 1, but int found 

I get this error while compiling a program.

  File "C:\Users\Administrator\Desktop\tracer1.py", line 129, in <module> get_route("www.google.com") File "C:\Users\Administrator\Desktop\tracer1.py", line 85, in get_route d = build_packet() File "C:\Users\Administrator\Desktop\tracer1.py", line 62, in build_packet myChecksum = checksum(header + data) File "C:\Users\Administrator\Desktop\tracer1.py", line 28, in checksum thisVal = ord(str[count+1]) * 256 + ord(str[count]) **TypeError: ord() expected string of length 1, but int found** 

program should find traceroute using ICMP

 from socket import * import socket import os import sys import struct import time import select import binascii import ctypes ICMP_ECHO_REQUEST = 8 MAX_HOPS = 30 TIMEOUT = 2.0 TRIES = 2 # The packet that we shall send to each router along the path is the ICMP echo # request packet, which is exactly what we had used in the ICMP ping exercise. # We shall use the same packet that we built in the Ping exercise ctypes.windll.shell32.IsUserAnAdmin() print (ctypes.windll.shell32.IsUserAnAdmin()) def checksum(str): csum = 0 countTo = (len(str) / 2) * 2 count = 0 while count < countTo: thisVal = ord(str[count+1]) * 256 + ord(str[count]) csum = csum + thisVal csum = csum & 0xffffffff count = count + 2 if countTo < len(str): csum = csum + ord(str[len(str) - 1]) csum = csum & 0xffffffff csum = (csum >> 16) + (csum & 0xffff) csum = csum + (csum >> 16) answer = ~csum answer = answer & 0xffff answer = answer >> 8 | (answer << 8 & 0xff00) return answer def build_packet(): # In the sendOnePing() method of the ICMP Ping exercise ,firstly the header of our # packet to be sent was made, secondly the checksum was appended to the header and # then finally the complete packet was sent to the destination. # Make the header in a similar way to the ping exercise. # Header is type (8), code (8), checksum (16), id (16), sequence (16) myChecksum = 0 pid = os.getpid() & 0xFFFF # Make a dummy header with a 0 checksum. # struct -- Interpret strings as packed binary data header = struct.pack("bbHHh", ICMP_ECHO_REQUEST, 0, myChecksum, pid, 1) #header = struct.pack("!HHHHH", ICMP_ECHO_REQUEST, 0, myChecksum, pid, 1) data = struct.pack("d", time.time()) # Calculate the checksum on the data and the dummy header. # Append checksum to the header. myChecksum = checksum(header + data) if sys.platform == 'darwin': myChecksum = socket.htons(myChecksum) & 0xffff #Convert 16-bit integers from host to network byte order. else: myChecksum = htons(myChecksum) packet = header + data return packet def get_route(hostname): timeLeft = TIMEOUT for ttl in range(1,MAX_HOPS): for tries in range(TRIES): destAddr = socket.gethostbyname(hostname) #Fill in start # Make a raw socket named mySocket mySocket = socket.socket(AF_INET, SOCK_RAW, getprotobyname("icmp")) mySocket.bind(("", 12000)); #Fill in end mySocket.setsockopt(socket.IPPROTO_IP, socket.IP_TTL, struct.pack('I', ttl)) mySocket.settimeout(TIMEOUT) try: d = build_packet() mySocket.sendto(d, (hostname, 0)) t = time.time() startedSelect = time.time() whatReady = select.select([mySocket], [], [], timeLeft) howLongInSelect = (time.time() - startedSelect) if whatReady[0] == []: # Timeout print ("* * * Request timed out.") recvPacket, addr = mySocket.recvfrom(1024) print ("addr") timeReceived = time.time() timeLeft = timeLeft - howLongInSelect if timeLeft <= 0: print ("* * * Request timed out.") except socket.timeout: continue else: #Fill in start # Fetch the icmp type from the IP packet print( struct.calcsize("bbHHhd")) request_code, request_type, checksum, packet_id, \ sequence, timeSent, data = struct.unpack("bbHHhd", recvPacket,0) #Fill in end if request_type == 11: bytes = struct.calcsize("d") timeSent = struct.unpack("d", recvPacket[28:28 + bytes])[0] print (" %d rtt=%.0f ms %s" % (ttl,(timeReceived -t)*1000, addr[0])) elif request_type == 3: bytes = struct.calcsize("d") timeSent = struct.unpack("d", recvPacket[28:28 + bytes])[0] print (" %d rtt=%.0f ms %s" % (ttl,(timeReceived -t)*1000, addr[0])) elif request_type == 0: bytes = struct.calcsize("d") timeSent = struct.unpack("d", recvPacket[28:28 + bytes])[0] print (" %d rtt=%.0f ms %s" % (ttl,(timeReceived -timeSent)*1000, addr[0])) return else: print ("error") break finally: mySocket.close() get_route("www.google.com") 

Answer 1

You are using a script using Python 3 where indexing the bytes object returns an integer:

 >>> b"abc"[1] 98 

Remove the calls to ord() . In this case, they are redundant.