Write an hexadecimal file

[Cesar Andres Roldan Garcia]

Hi

I'm trying to write an hexadecimal file... I mean not a text plain...
I have to convert a float decimal number in float hexadecimal one, and
that's done.

That number is the one I'm gonna write in the hex file... can anybody
help me 'cause i don't know how python write an hex file!

Thanks!

--
Atentamente,

Cesar Andres Roldan Garcia
Presidente Comunidad Académica Microsoft Javeriana
Cali - Colombia

[Larry Bates]

Re: Write an hexadecimal file

There is not such thing as a hexadecimal file. Files are either
binary or text. Hexadecimal is a representation of binary data
where 4 bits are displayed as a single hex digit (0-F) as
shorthand (because 111100000111100 0111 is just too difficult to
deal with).

To write binary data to a file in Python you open the file with
"wb" mode.

Example:

fp=open('myfile .dat', 'wb')
fp.write(bytes)
fp.close()

From your post I cannot tell anything more about what you are
actually doing, so I hope this helps.

Larry Bates


Cesar Andres Roldan Garcia wrote:[color=blue]
> Hi
>
> I'm trying to write an hexadecimal file... I mean not a text plain...
> I have to convert a float decimal number in float hexadecimal one, and
> that's done.
>
> That number is the one I'm gonna write in the hex file... can anybody
> help me 'cause i don't know how python write an hex file!
>
> Thanks!
>[/color]

[Raymond Hettinger]

Re: Write an hexadecimal file

[Cesar Andres Roldan Garcia][color=blue]
> I'm trying to write an hexadecimal file... I mean not a text plain...
>I have to convert a float decimal number in float hexadecimal one,
> and that's done.[/color]

The struct module provides a portable way to convert a float to and from a
sequence of bytes.

The binascii modules provides tools for converting a sequence of bytes to and
from a representation as a hex string.
[color=blue][color=green][color=darkred]
>>> import struct, binascii
>>> binascii.hexlif y(struct.pack(' >f', 3.1415926535))[/color][/color][/color]
'40490fdb'[color=blue][color=green][color=darkred]
>>> struct.unpack(' >f', binascii.unhexl ify(_))[0][/color][/color][/color]
3.1415927410125 732

Writing to a file is accomplished with the open() function and the file.write()
method:

f = open('mydata.he x', 'w')
f.write('40490f db')
f.close()



Raymond Hettinger

[rbt]

Re: Write an hexadecimal file

Larry Bates wrote:[color=blue]
> There is not such thing as a hexadecimal file.[/color]

Right, 300 is 300 whether you choose to represent it in decimal, binary,
hex, etc... it's still only 300 of something ;)