Convert hex string to float

Question

I am trying to read from a file a bunch of hex numbers.

lines ='4005297103CE40C040059B532A7472C440061509BB9597D7400696DBCF1E35CC4007206BB5B0A67B4007AF4B08111B87400840D4766460524008D47E0FFB4ABA400969A572EBAFE7400A0107CCFDF50E'
dummy = [lines[index][i:i+16] for i in range(0, len(lines[index]),16)]
rdummy=[]
for elem in dummy[:-1]:
 
                rdummy.append(int(elem,16))

these are 10 number of 16 digits in particular when reading the first one, I have:

print(dummy[0])
4005297103CE40C0

now I would like to convert it to float

I have an IDL script that when reading this number gives 2.64523509

the command used in IDL is

double(4613138958682833088,0)

where it appers 0 is an offset used when converting.

is there a way to do this in python?

Your problem should be solved by the answer given here: https://stackoverflow.com/questions/1592158/convert-hex-to-float — Siddharth Pandalai, Jun 26 '20 at 15:36
Does this answer your question? [Convert hex to float](https://stackoverflow.com/questions/1592158/convert-hex-to-float) — MLavrentyev, Jun 26 '20 at 15:37
I don't see how a 16-digit hex number can give a float value of 2.6. Something else is going on. — John Gordon, Jun 26 '20 at 15:43
int('4005297103CE40C0', base=16) yields 4613138958682833088. now if I go on my IDL console and I cast to double---> double(4613138958682833088,0) = 2.6452350899999999. I just want to understand how to do this last casting in pYthon — bruvio, Jun 26 '20 at 16:00

score 1 · Accepted Answer · answered Jun 26 '20 at 16:19

you probably want to use the struct package for this, something like this seems to work:

import struct

lines ='4005297103CE40C040059B532A7472C440061509BB9597D7400696DBCF1E35CC4007206BB5B0A67B4007AF4B08111B87400840D4766460524008D47E0FFB4ABA400969A572EBAFE7400A0107CCFDF50E'

for [value] in struct.iter_unpack('>d', bytes.fromhex(lines)):
  print(value)

results in 2.64523509 being printed first which seems about right

Convert hex string to float

1 Answers1