[fixed top-posting]
Rami Chowdhury wrote:
On Thu, 20 Aug 2009 14:08:34 -0700, Matthias Güntert
<matzeguent...@gmx.de> wrote:
Hello guys
I would like to read a hex number from an ASCII file, increment it and
write it back.
How can this be performed?
I have tried several approaches:
my file serial.txt contains: 0C
----------------------------------
f = open('serial.txt', 'r')
val = f.read()
val = val.encode('hex')
That's the crucial line -- it's returning a new integer, which you are
re-binding to val. If you then did:
val = val + 1
you'd be fine, and could then write val back to your file :-)
.encode('hex') is returning a string -- attempting to add one to it will
raise the same error the OP is getting below.
To get a number you can do (after reading val from the file):
val = int(val, '16') # convert from base 16
val += 1 # increment
val = "%X" % val # back to heg digits
and then write it back out again. Don't forget to close and reopen the
file for writing. :)
~Ethan~
print val
----------------------------------
--> 3043
----------------------------------
f = open('serial.txt', 'r')
val = f.read()
print val
val = val+1
----------------------------------
--> TypeError: cannot concatenate 'str' and 'int' objects
----------------------------------
f = open('serial.txt', 'rb')
val = f.read()
val = val + 1
----------------------------------
--> TypeError: cannot concatenate 'str' and 'int' objects
hm....
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