difficult string conversion need help

difficult string conversion need help - Printable Version

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difficult string conversion need help - Pir8Radio - Nov-27-2022

difficult for me anyway... I have a long hex little endian string... within this string are 9 sets of 16 characters. this string can vary from 3 sets of 16 to many sets of 16 characters... I only need the first 16 characters of each set of 3. I need to convert these 16 characters to decimal from hex little endian..

Example here is a string: 2692692A7BAE0E47430678A4B4382D13F032AE1C509ED523EF747FF795260E917A0DA53F07140C408DA814235B0A2BDD3EBA832D8F2C82FE0AD1B0FD092515A475C04BC130D77E3C

that string broken out looks like: 2692692A7BAE0E47 430678A4B4382D13 F032AE1C509ED523 EF747FF795260E91 7A0DA53F07140C40 8DA814235B0A2BDD 3EBA832D8F2C82FE 0AD1B0FD092515A4 75C04BC130D77E3C

The only blocks i care about is the first, skip two, next, skip two, next and so on.. so i need the ones in bold.. and i need to convert them to dec..
2692692A7BAE0E47 = 5120221670382604838
EF747FF795260E91 = 10452334210717807855
3EBA832D8F2C82FE = 18339269626061634110

again this string can contain one set of three or 30 sets of 3 and i only need the first set of each

Help would be appreciated lol.. im loosing it over here..

RE: difficult string conversion need help - Gribouillis - Nov-27-2022

It is easy to extract the substrings, but where do you get the integer values from?

>>> s = '2692692A7BAE0E47430678A4B4382D13F032AE1C509ED523EF747FF795260E917A0DA53F07140C408DA814235B0A2BDD3EBA832D8F2C82FE0AD1B0FD092515A475C04BC130D77E3C'
>>> for x in (s[k:k+16] for k in range(0, len(s), 3*16)):
...     print(x)
... 
2692692A7BAE0E47
EF747FF795260E91
3EBA832D8F2C82FE
>>>

Edit: I think I've found a way

>>> from binascii import a2b_hex
>>> import struct
>>> 
>>> s = '2692692A7BAE0E47430678A4B4382D13F032AE1C509ED523EF747FF795260E917A0DA53F07140C408DA814235B0A2BDD3EBA832D8F2C82FE0AD1B0FD092515A475C04BC130D77E3C'
>>> 
>>> for x in (s[k:k+16] for k in range(0, len(s), 3*16)):
...     z = a2b_hex(x)
...     i = struct.unpack('<Q', z)[0]
...     print(x, i)
... 
2692692A7BAE0E47 5120221670382604838
EF747FF795260E91 10452334210717807855
3EBA832D8F2C82FE 18339269626061634110

RE: difficult string conversion need help - Pir8Radio - Nov-27-2022

you suck... lol (joking) I'm just jealous Angel

I racked my brain, I still have a lot of learning to do... Cry

thank you so much for turning this around so quick.. and in such efficient code.. i really appreciate it! Let me get this into the rest of my project and see how it works!!!! thank you again!!!!!!!!!!

RE: difficult string conversion need help - Gribouillis - Nov-27-2022

Thanks, that was easy.

According to the documentation, one can use bytes.fromhex() instead of a2b_hex(). It's a little prettier

import struct

s = '2692692A7BAE0E47430678A4B4382D13F032AE1C509ED523EF747FF795260E917A0DA53F07140C408DA814235B0A2BDD3EBA832D8F2C82FE0AD1B0FD092515A475C04BC130D77E3C'

for x in (s[k:k+16] for k in range(0, len(s), 3*16)):
    i = struct.unpack('<Q', bytes.fromhex(x))[0]
    print(x, i)