How can I produce a hex-escaped string in python that I can use in C++?

Question

I'm trying to create synthesized unit tests for a library that uses MessagePack. I would like to create hex-escaped binary strings in python that I can embed in C++ sources. I'm creating one like this:

In [6]: umsgpack.packb([0, 0, 'dummy_void_zeroarg', []])
Out[6]: '\x94\x00\x00\xc4\x12dummy_void_zeroarg\x90'

However, it looks like the resulting hex string is almost, but not quite usable in C++:

error: hex escape sequence out of range
        "\x94\x00\x00\xc4\x12dummy_void_zeroarg\x90";
                         ^~~~~

The reason is that the compiler tries to parse \x12d as a single value. Is there a way to transform the above hex string to one in python that does not contain letters (i.e. only \x items)?

Answer 1

You'll have to do so manually:

"'{}'".format(''.join(['\\x{:02x}'.format(ord(c)) for c in message]))

Print the result or write it to a file:

>>> print "'{}'".format(''.join(['\\x{:02x}'.format(ord(c)) for c in message]))
'\x94\x00\x00\xc4\x12\x64\x75\x6d\x6d\x79\x5f\x76\x6f\x69\x64\x5f\x7a\x65\x72\x6f\x61\x72\x67\x90'