What's the correct way to convert bytes to a hex string in Python 3?
I see claims of a bytes.hex
method, bytes.decode
codecs, and have tried other possible functions of least astonishment without avail. I just want my bytes as hex!
What's the correct way to convert bytes to a hex string in Python 3?
I see claims of a bytes.hex
method, bytes.decode
codecs, and have tried other possible functions of least astonishment without avail. I just want my bytes as hex!
Since Python 3.5 this is finally no longer awkward:
>>> b'\xde\xad\xbe\xef'.hex()
'deadbeef'
and reverse:
>>> bytes.fromhex('deadbeef')
b'\xde\xad\xbe\xef'
works also with the mutable bytearray
type.
Reference: https://docs.python.org/3/library/stdtypes.html#bytes.hex
bytes.fromhex()
is also available on Python 3.0+ (not just 3.5+). bytes.hex()
is only on Python 3.5+.
Commented
Jun 13, 2018 at 14:16
Use the binascii
module:
>>> import binascii
>>> binascii.hexlify('foo'.encode('utf8'))
b'666f6f'
>>> binascii.unhexlify(_).decode('utf8')
'foo'
See this answer: Python 3.1.1 string to hex
str
but a bytes
. I know that the OP seems happy with the answer but won't be better to expand this answer to include .decode("ascii")
also to convert it to a "string"
Commented
Jun 8, 2015 at 17:11
bytes
. If you print(b'666f6f')
you get the b
in the printout. If you .decode("ascii")
then you don't. Just thinking on how those that actually had a bytes
(true binary with items > 128 , not an ascii string) an wanted to printout it.
Commented
Jun 9, 2015 at 5:52
Python has bytes-to-bytes standard codecs that perform convenient transformations like quoted-printable (fits into 7bits ascii), base64 (fits into alphanumerics), hex escaping, gzip and bz2 compression. In Python 2, you could do:
b'foo'.encode('hex')
In Python 3, str.encode
/ bytes.decode
are strictly for bytes<->str conversions. Instead, you can do this, which works across Python 2 and Python 3 (s/encode/decode/g for the inverse):
import codecs
codecs.getencoder('hex')(b'foo')[0]
Starting with Python 3.4, there is a less awkward option:
codecs.encode(b'foo', 'hex')
These misc codecs are also accessible inside their own modules (base64, zlib, bz2, uu, quopri, binascii); the API is less consistent, but for compression codecs it offers more control.
LookupError: unknown encoding: hex
Commented
Mar 5, 2014 at 22:37
binascii.hexlify(b'foo')
directly
New in python 3.8, you can pass a delimiter argument to the hex
function, as in this example
>>> value = b'\xf0\xf1\xf2'
>>> value.hex('-')
'f0-f1-f2'
>>> value.hex('_', 2)
'f0_f1f2'
>>> b'UUDDLRLRAB'.hex(' ', -4)
'55554444 4c524c52 4142'
[f'0x{val}' for val in value.hex(' ', 2).split()]
gives something like ['0x2600', '0x9c00', '0x1900', '0x0c75']
Commented
Apr 28, 2022 at 14:10
The method binascii.hexlify()
will convert bytes
to a bytes
representing the ascii hex string. That means that each byte in the input will get converted to two ascii characters. If you want a true str
out then you can .decode("ascii")
the result.
I included an snippet that illustrates it.
import binascii
with open("addressbook.bin", "rb") as f: # or any binary file like '/bin/ls'
in_bytes = f.read()
print(in_bytes) # b'\n\x16\n\x04'
hex_bytes = binascii.hexlify(in_bytes)
print(hex_bytes) # b'0a160a04' which is twice as long as in_bytes
hex_str = hex_bytes.decode("ascii")
print(hex_str) # 0a160a04
from the hex string "0a160a04"
to can come back to the bytes
with binascii.unhexlify("0a160a04")
which gives back b'\n\x16\n\x04'
import codecs
codecs.getencoder('hex_codec')(b'foo')[0]
works in Python 3.3 (so "hex_codec" instead of "hex").
it can been used the format specifier %x02
that format and output a hex value. For example:
>>> foo = b"tC\xfc}\x05i\x8d\x86\x05\xa5\xb4\xd3]Vd\x9cZ\x92~'6"
>>> res = ""
>>> for b in foo:
... res += "%02x" % b
...
>>> print(res)
7443fc7d05698d8605a5b4d35d56649c5a927e2736
res.upper()
upper()
!. You can control case by x
or X
: '%02X' % 79 == '4F'
OK, the following answer is slightly beyond-scope if you only care about Python 3, but this question is the first Google hit even if you don't specify the Python version, so here's a way that works on both Python 2 and Python 3.
I'm also interpreting the question to be about converting bytes to the str
type: that is, bytes-y on Python 2, and Unicode-y on Python 3.
Given that, the best approach I know is:
import six
bytes_to_hex_str = lambda b: ' '.join('%02x' % i for i in six.iterbytes(b))
The following assertion will be true for either Python 2 or Python 3, assuming you haven't activated the unicode_literals
future in Python 2:
assert bytes_to_hex_str(b'jkl') == '6a 6b 6c'
(Or you can use ''.join()
to omit the space between the bytes, etc.)
sep
arg in bytes.hex
. At time of writing, 3.7 is still a supported version.
Commented
Mar 2, 2023 at 17:11
If you want to convert b'\x61' to 97 or '0x61', you can try this:
[python3.5]
>>>from struct import *
>>>temp=unpack('B',b'\x61')[0] ## convert bytes to unsigned int
97
>>>hex(temp) ##convert int to string which is hexadecimal expression
'0x61'