decrypt str in dictionary using bytes and fernet - json

Question

I am trying to decrypt encrypted strs that are inside of a dictionary. To do this, the values must first be encoded, then the data can be decrypted and then decoded. I am struggling to encode the values without encoding the keys.
P.S: here is the printout for line 4:
b'{"pid": 6, "parent_first": "gAAAAABjAsAWbyxBsR804rVdMJ_Dzfj1s5s9GYVFSB2AJq3VSHTjH2V7lE4lt2gtO3LrhL6eKTm1qx153VO-g5xxWRb6mjXqvQ==", "parent_last": "gAAAAABjAsAWgiUupGo06d-tLY3WHgpfu5g0y55DjCPXdx4G2hIkEw50e3HAyi_r6z5NBHnJkevR8WkAy-2mhjvhUFRUk7Le8Q==", "email": "gAAAAABjAsAWAOTCver2_4bsBfrDA8SIdrykIH8Jojkd5100HT9y2Yz6ZnbZfYBqOYgwcKEquFhRGRZtey0A1Mdu12GxSHD3OdN8zb1DlLF0cP6O9tZEHGc=", "password": "f58a1612e9af7b5ee7e2141730f9a680f94765ad082918d489be42bde5d9ab23", "username": "9e7bd6851718b496e3c9cb0db480cbb8b87cf0455a7d627658906158357849b1"}'
for user in query:
dict = user.to_dict()
res_bytes = json.dumps(dict).encode('utf-8')
print(res_bytes)
res_bytes['parent_first'] = decrypt(res_bytes['parent_first'.encode('utf-8')])
res_bytes['parent_last'] = decrypt(res_bytes['parent_last'.encode('utf-8')])
res_bytes['email'] = decrypt(res_bytes['email'.encode('utf-8')])
res_bytes['username'] = decrypt(res_bytes['username'.encode('utf-8')])
dict = json.loads(res_bytes)
print(dict)
this gives an error of byte indices must be integers or slices, not bytes

Answer 1

res_bytes contains a byte sequence, so trying to work with it as if it's a dictionary instance doesn't make sense and results in the error you're seeing.
Basically, there's no reason to use json.dumps() and json.loads() in this code snippet.
Instead, try something like:
for user in query:
u = user.to_dict()
u['parent_first'] = decrypt(u['parent_first'])
u['parent_last'] = decrypt(u['parent_last'])
u['email'] = decrypt(u['email'])
u['username'] = decrypt(u['username'])
print(u)
A few notes:
Once you've converted user to a dictionary, proceed to use it as a dictionary.
Fernet.decrypt() can take either a str or bytes as input, so no need to worry about encoding/decoding it.