在Python中将0x字符串解释为十六进制

Question

I'm appending some hex bytes into a packet = [] and I want to return these hex bytes in the form of 0x__ as hex data.

packet.append("2a")
packet.append("19")
packet.append("00")
packet.append("00")

packHex = []

for i in packet:
    packHex.append("0x"+i) #this is wrong

return packHex

How do I go about converting ('2a', '19', '00', '00') in packet to get (0x2a, 0x19, 0x0, 0x0) in packHex ? I need real hex data, not strings that look like hex data.

I'm assembling a packet to be sent over pcap , pcap_sendpacket(fp,packet,len(data)) where packet should be a hexadecimal list or tuple for me, maybe it can be done in decimal, haven't tried, I prefer hex. Thank you for your answer.

packetPcap[:len(data)] = packHex

Solved:

for i in packet: packHex.append(int(i,16))

If output in hex needed, this command can be used: print ",".join(map(hex, packHex))

Answer 1

You don't really want 'hex data', you want integers. Hexadecimal notation only makes sense when you have numbers represented as strings.

To solve your problem use a list comprehension:

[int(x, 16) for x in packet]

Or to get the result as a tuple:

tuple(int(x, 16) for x in packet)

Answer 2

Why don't you just build a list of int s and just print them out in base 16 (either by using "%x"%value or hex ) instead? If the values are given to you in this form (eg from some other source), you can use int with the optional second parameter to turn this into an int .

>>> int('0x'+'2a',16)
42
>>> packet=["2a","19","00","00"]
>>> packet=[int(p,16) for p in packet]
>>> packet
[42, 25, 0, 0]
>>> print ", ".join(map(hex,packet))
0x2a, 0x19, 0x0, 0x0

Answer 3

Say you have a list = ["2a", "19", "00", "00"]

For me I use list = [hex(int(i, 16)) for i in vals]

It then returns a new list with hex type of all the elements.

>>>['0x2a', '0x19', '0x0', '0x0']