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Make code copy-pasteable. Clarify excerpt.
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wjandrea
wjandrea
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I have bytes in Python: b'P\xf3g9\xea\xc3'

I know that this is an IP address and I know how to convert it to one (this is based on BitTorrent specificationBitTorrent specification -> the peers"the peers value may be a string consisting of multiples of 6 bytes. First 4 bytes are the IP address and last 2 bytes are the port number. All in network (big endian) notation url."):

import socket import struct p = `b'P\xf3g9\xea\xc3'`b'P\xf3g9\xea\xc3' print(f'peer {p}: bytes IP: {p[:4]}; bytes PORT: {p[4:]}') >>># > peer b'P\xf3g9\xea\xc3': bytes IP: b'P\xf3g9'; bytes PORT: b'\xea\xc3'   print('IP', socket.inet_ntoa(p[:4])) >>># -> IP 80.243.103.57   # > - big-endian; H - unsigned short print('PORT', struct.unpack(">H", p[4:])[0]) >>># -> PORT 60099

I'm struggling to understand how this works? Ideally I would like to understand how to convert bytes to the IP address by hand.

Some questions that I have:

  • what is the leading P in bytes?
  • how to transform this represntation (i assume it's hex?) to base 2?
  • I think I understand \xf3 -> that translates to 243. What abaout g9?

Would be great if some one could explain or point somewhere where I can read more about it.

I have bytes in Python: b'P\xf3g9\xea\xc3'

I know that this is an IP address and I know how to convert it to one (this is based on BitTorrent specification -> the peers value may be a string consisting of multiples of 6 bytes. First 4 bytes are the IP address and last 2 bytes are the port number. All in network (big endian) notation url):

import socket import struct p = `b'P\xf3g9\xea\xc3'` print(f'peer {p}: bytes IP: {p[:4]}; bytes PORT: {p[4:]}') >>> peer b'P\xf3g9\xea\xc3': bytes IP: b'P\xf3g9'; bytes PORT: b'\xea\xc3' print('IP', socket.inet_ntoa(p[:4])) >>> IP 80.243.103.57 # > - big-endian; H - unsigned short print('PORT', struct.unpack(">H", p[4:])[0]) >>> PORT 60099

I'm struggling to understand how this works? Ideally I would like to understand how to convert bytes to the IP address by hand.

Some questions that I have:

  • what is the leading P in bytes?
  • how to transform this represntation (i assume it's hex?) to base 2?
  • I think I understand \xf3 -> that translates to 243. What abaout g9?

Would be great if some one could explain or point somewhere where I can read more about it.

I have bytes in Python: b'P\xf3g9\xea\xc3'

I know that this is an IP address and I know how to convert it to one (this is based on BitTorrent specification -> "the peers value may be a string consisting of multiples of 6 bytes. First 4 bytes are the IP address and last 2 bytes are the port number. All in network (big endian) notation."):

import socket import struct p = b'P\xf3g9\xea\xc3' print(f'peer {p}: bytes IP: {p[:4]}; bytes PORT: {p[4:]}') # > peer b'P\xf3g9\xea\xc3': bytes IP: b'P\xf3g9'; bytes PORT: b'\xea\xc3'   print('IP', socket.inet_ntoa(p[:4])) # -> IP 80.243.103.57   # > - big-endian; H - unsigned short print('PORT', struct.unpack(">H", p[4:])[0]) # -> PORT 60099

I'm struggling to understand how this works? Ideally I would like to understand how to convert bytes to the IP address by hand.

Some questions that I have:

  • what is the leading P in bytes?
  • how to transform this represntation (i assume it's hex?) to base 2?
  • I think I understand \xf3 -> that translates to 243. What abaout g9?

Would be great if some one could explain or point somewhere where I can read more about it.

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public_secrets
public_secrets
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How are bytes represented and converted from one format to anoter

I have bytes in Python: b'P\xf3g9\xea\xc3'

I know that this is an IP address and I know how to convert it to one (this is based on BitTorrent specification -> the peers value may be a string consisting of multiples of 6 bytes. First 4 bytes are the IP address and last 2 bytes are the port number. All in network (big endian) notation url):

import socket import struct p = `b'P\xf3g9\xea\xc3'` print(f'peer {p}: bytes IP: {p[:4]}; bytes PORT: {p[4:]}') >>> peer b'P\xf3g9\xea\xc3': bytes IP: b'P\xf3g9'; bytes PORT: b'\xea\xc3' print('IP', socket.inet_ntoa(p[:4])) >>> IP 80.243.103.57 # > - big-endian; H - unsigned short print('PORT', struct.unpack(">H", p[4:])[0]) >>> PORT 60099

I'm struggling to understand how this works? Ideally I would like to understand how to convert bytes to the IP address by hand.

Some questions that I have:

  • what is the leading P in bytes?
  • how to transform this represntation (i assume it's hex?) to base 2?
  • I think I understand \xf3 -> that translates to 243. What abaout g9?

Would be great if some one could explain or point somewhere where I can read more about it.