CODEWITHSUNDEEP
pythonstringescaping
Andrew Wagner
Andrew Wagner

Reputation: 24547

Print string as hex literal python

I have a lot of pre-existing code that treats byte arrays as strings, i.e. 

In [70]: x = '\x01\x41\x42\x43'

Which python always prints as:

In [71]: x
Out[71]: '\x01ABC'

This makes debugging a pain, since the strings I print don't look like the literals in my code. How to I print strings as hex literals?

Upvotes: 5

Views: 8202

Answers (4)

Olivier Lasne
Olivier Lasne

Reputation: 981

In python3, I generally write a small function to do this.

def print_hex_string(data):
    result = ''

    for c in data:
        result += f'\\x{c:02x}'

    print("b'" + result + "'")

x = b'\x01\x41\x42\x43'
print(x)
# b'\x01ABC'

print_hex_string(x)
# b'\x01\x41\x42\x43'

binascii is not needed since you can just do x.hex() for the same result.

print(x.hex())
# 01414243

oneliner:

x = b'\x01\x41\x42\x43'
print(''.join([f'\\x{c:02x}' for c in x]))
# \x01\x41\x42\x43

Upvotes: 0

Andrew Wagner
Andrew Wagner

Reputation: 24547

To actually print out the string ~literal (i.e. the thing you can cut and paste back into your code to get the same object) requires something like:

>>> x = '\x1\41\42\43'
>>> print "'" + ''.join(["\\"+ hex(ord(c))[-2:] for c in x]) + "'"
'\x1\41\42\43'

Upvotes: 0

agf
agf

Reputation: 176780

For a cross-version compatible solution, use binascii.hexlify:

>>> import binascii
>>> x = '\x01\x41\x42\x43'
>>> print x
ABC
>>> repr(x)
"'\\x01ABC'"
>>> print binascii.hexlify(x)
01414243

As .encode('hex') is a misuse of encode and has been removed in Python 3:

Python 3.3.1
Type "help", "copyright", "credits" or "license" for more information.
>>> '\x01\x41\x42\x43'.encode('hex')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
LookupError: unknown encoding: hex

Upvotes: 2

Vor
Vor

Reputation: 35109

You can try something like this:

>>> x = '\x01\x41\x42\x43'
>>> x.encode('hex')
'01414243'

or

>>> x = r'\x01\x41\x42\x43'
>>> x
'\\x01\\x41\\x42\\x43'

or

>>> x = '\x01\x41\x42\x43'
>>> print " ".join(hex(ord(n)) for n in x)
0x1 0x41 0x42 0x43

Upvotes: 1

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