Concise way to format list/array to custom(hex) string

[Kurien Mathew]

Hello,

What will be a concise & efficient way to convert a list/array.array of
n elements into a hex string? For e.g. given the bytes
[116, 111, 110, 103, 107, 97]
I would like the formatted string
0x74 0x6f 0x6e 0x67 0x6b 0x61

Is there an approach better than below:
hex = ''
for b in bytes:
hex += ('0x%x '%b)


Thanks
Kurien

Test program:
import array
import sys

bytes = array.array('B' )
bytes.fromstrin g("tongka")
print bytes
hex = ''
for b in bytes:
hex += ('0x%x '%b)
print hex

[John Machin]

Re: Concise way to format list/array to custom(hex) string

On Aug 2, 9:53 pm, Kurien Mathew <kmat...@envivi o.frwrote:

Hello,
>
What will be a concise & efficient way to convert a list/array.array of
n elements into a hex string? For e.g. given the bytes
[116, 111, 110, 103, 107, 97]
I would like the formatted string
0x74 0x6f 0x6e 0x67 0x6b 0x61
>
Is there an approach better than below:
hex = ''
for b in bytes:
hex += ('0x%x '%b)
>

hex = ' '.join('0x%02x' % b for b in bytes)

[=?ISO-8859-1?Q?Zolt=E1n_Nagy?=]

Re: Concise way to format list/array to custom(hex) string

Kurien Mathew írta:

Hello,
>
What will be a concise & efficient way to convert a list/array.array of
n elements into a hex string? For e.g. given the bytes
[116, 111, 110, 103, 107, 97]
I would like the formatted string
0x74 0x6f 0x6e 0x67 0x6b 0x61
>
Is there an approach better than below:
hex = ''
for b in bytes:
hex += ('0x%x '%b)
>

<snip>

You should avoid multiple string additions, as each one creates a new
string object (str objects are immutable). Try this:

bytes = [116, 111, 110, 103, 107, 97]
string = ''.join( ['0x%x '%b for b in bytes] )

[Grant Edwards]

Re: Concise way to format list/array to custom(hex) string

On 2008-08-02, Zoltán Nagy <abesto0@gmail. comwrote:

Kurien Mathew írta:

>Hello,
>>
>What will be a concise & efficient way to convert a list/array.array of
>n elements into a hex string? For e.g. given the bytes
>[116, 111, 110, 103, 107, 97]
>I would like the formatted string
>0x74 0x6f 0x6e 0x67 0x6b 0x61
>>
>Is there an approach better than below:
>hex = ''
>for b in bytes:
> hex += ('0x%x '%b)
>>

><snip>
>
You should avoid multiple string additions, as each one creates a new
string object (str objects are immutable). Try this:
>
bytes = [116, 111, 110, 103, 107, 97]
string = ''.join( ['0x%x '%b for b in bytes] )

That results in an extra ' ' and the end of the string. Try
this:

string = ' '.join(['0x%02x' % b for b in bytes])

--
Grant Edwards grante Yow! ... Just enough
at time to do my LIBERACE
visi.com impression...

[josh logan]

Re: Concise way to format list/array to custom(hex) string

On Aug 2, 9:29 am, Grant Edwards <gra...@visi.co mwrote:

On 2008-08-02, Zoltán Nagy <abes...@gmail. comwrote:
>
>
>
>
>

Kurien Mathew írta:

Hello,

>

What will be a concise & efficient way to convert a list/array.array of
n elements into a hex string? For e.g. given the bytes
[116, 111, 110, 103, 107, 97]
I would like the formatted string
0x74 0x6f 0x6e 0x67 0x6b 0x61

>

Is there an approach better than below:
hex = ''
for b in bytes:
    hex += ('0x%x '%b)

>

<snip>

>

You should avoid multiple string additions, as each one creates a new
string object (str objects are immutable). Try this:

>

bytes = [116, 111, 110, 103, 107, 97]
string = ''.join( ['0x%x '%b for b in bytes] )

>
That results in an extra ' ' and the end of the string.  Try
this:
>
string = ' '.join(['0x%02x' % b for b in bytes])
>
--
Grant Edwards                   grante             Yow!  ... Just enough
                                  at               time to do my LIBERACE
                               visi.com            impression...

There is also a built-in hex() method in the Python Standard Library.
So, to make it cleaner:
' '.join(hex(x) for x in bytes)