Encode/decode specific character in string with hex notation using Python 2.7

Question

How can I encode string 'banana', so that all a's become \\x97 like this?

b\x97n\x97n\x97

Then, how can I reverse or decode a string with embedded hex values back to the original string banana?

Answer 1

Use str.replace to replace that character with the hex representation of its ordinal value. And to get the actual string back you can decode it using string-decode .

>>> s = 'banana'
>>> print s.replace('a', '\\x' + format(ord('a'), 'x'))
b\x61n\x61n\x61
>>> print s.replace('a', '\\x' + format(ord('a'), 'x')).decode('string-escape')
banana

Answer 2

To do it and keep the encoding as standard ASCII not hex...

import re
s = 'banana'
t = s.replace('a', '\\x{}'.format(ord('a')))
subs = re.findall(r'\\x\d{2}',t)
decoded = ""
for match in set(subs):
    decoded = t.replace(match, chr(int(match[2:4]))
print decoded