pack an integer into a string

[casevh]

On Jul 24, 3:28 pm, superpollo <u... at example.net> wrote:
> is there a pythonic and synthetic way (maybe some standard module) to
> "pack" an integer (maybe a *VERY* big one) into a string? like this:
>
>   >>> number = 252509952
>   >>> hex(number)
>   '0xf0cff00'
>   >>>
>
> so i would like a string like '\xf0\xcf\xf0\x00'
>
> i wrote some code to do it, so ugly i am ashamed to post :-(
>
> i tried xdrlib, but does not quite do what i mean...
>
> bye

This works, I think.

>>> def hex_string(n):
...     a = hex(n)
...     ch_list = []
...     if a.startswith('0x'): a = a[2:]
...     if a.endswith('L'): a = a[:-1]
...     for i in range(0, len(a)):
...         ch_list.append(chr(int(a[i:i+2],16)))
...     return ''.join(ch_list)
...
>>> hex_string(252509952)
'\xf0\x0c\xcf\xff\xf0\x00\x00'
>>> hex_string(283691163101781L)
'\x10\x02 \x03?\xff\xf0\x00\n\xaa\xa5U\x05'
>>>