Convert a Bytes String to Dictionary in Python - json

Question

Basic Information
I am creating a python script that can encrypt and decrypt a file with previous session data.
The Problem
I am able to decrypt my file and read it using a key. This returns a bytes string which I can in turn convert to a string. However, this string needs to be converted to a dictionary, which I cannot do. Using ast, json and eval I have run into errors.
Bytes string
decrypted = fernet.decrypt(encrypted)
String
string = decrypted.decode("UTF-8").replace("'", '"')
If I use eval() or ast.literal_eval() I get the following error:
Then I tried using json.loads() and I get the following error:
The information blocked out on both images is to protect my SSH connections. In the first image it is giving me a SyntaxError at the last digit of my ip address.
The Function
The function that is responsible for this when called looks like this:
def FileDecryption():
with open('enc_key.key', 'rb') as filekey:
key = filekey.read()
filekey.close()
fernet = Fernet(key)
with open('saved_data.txt', 'rb') as enc_file:
encrypted = enc_file.read()
enc_file.close()
decrypted = fernet.decrypt(encrypted)
print(decrypted)
string = decrypted.decode("UTF-8").replace("'", '"')
data = f'{string}'
print(data)
#data = eval(data)
data = json.loads(data)
print(type(data))
for key in data:
#command_string = ["load", data[key][1], data[key][2], data[key][3], data[key][4]]
#SSH.CreateSSH(command_string)
print(key)
Any help would be appreciated. Thanks!

Answer 1

Your data seems like it was written incorrectly in the first place, but without a complete example hard to say.
Here's a complete example that round-trips a JSON-able data object.
# requirement:
# pip install cryptography
from cryptography.fernet import Fernet
import json
def encrypt(data, data_filename, key_filename):
key = Fernet.generate_key()
with open(key_filename, 'wb') as file:
file.write(key)
fernet = Fernet(key)
encrypted = fernet.encrypt(json.dumps(data).encode())
with open(data_filename, 'wb') as file:
file.write(encrypted)
def decrypt(data_filename, key_filename):
with open(key_filename, 'rb') as file:
key = file.read()
fernet = Fernet(key)
with open(data_filename, 'rb') as file:
return json.loads(fernet.decrypt(file.read()))
data = {'key1': 'value1', 'key2': 'value2'}
encrypt(data, 'saved_data.txt', 'enc_key.key')
decrypted = decrypt('saved_data.txt', 'enc_key.key')
print(decrypted)
Output:
{'key1': 'value1', 'key2': 'value2'}