Python string-bytes to bytes

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I have string data that look like bytes reprs of JSON in Python

>>> data = """b'{"a": 1, "b": 2}\n'"""

So on the inside of that, we have valid JSON that looks like it's been byte-encoded. I want to decode the bytes and loads the JSON on the inside, but since its a string I cannot.

>>> data.decode() # nope
AttributeError: 'str' object has no attribute 'decode'

Encoding the string doesn't seem to help either:

>>> data.encode() # wrong
b'b\'{"a": 1, "b": 2}\n\''

There are oodles of string-to-bytes questions on stackoverflow, but for the life of me I cannot find anything about this particular issue. Does anyone know how this can be accomplished?

Things that I do not want to do and/or will not work:

  1. eval the data into a bytes object
  2. strip the b and \n (inside of my JSON there's all sorts of other escaped data).

This is the only working solution I have found, and there is a lot not to like about it:

from ast import literal_eval

data = """b'{"a": 1, "b": 2}\n'"""
print(literal_eval(data[:-2] + data[-1:]).decode('utf-8'))
unicode python string
1 Answers

I know you said you didn't want to strip the b inside the string due to other escaped data, but can't we assume that whatever generated this only output ascii (hence the b), and we can re-encode that. So I was thinking you can use a simple regexp (https://regex101.com/r/M0ratk/1) which you then encode as bytes.

import json
import re

match = re.match(r"\Ab'(.*)'\Z", data, re.DOTALL)
data = json.loads(bytes(match[1], 'ascii'))

Will this work? I am not sure how it compares to the literal_eval solution.

user_2884480
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