Update Prostgres Persistence

[Bibo-Joshi]

I started out with just updating to v20, but ended up also

• refactoring the internals to better leverage the parent class DictPersistence and
• adding support for callback_data

Unfortunately I'm not familiar for postgres (& databases in general), so I didn't try to actually test this with a real database (instead of just mocking as in the tests). If would be great if someone could cover that part :) CCing @starry69 for completeness 🙆‍♂️

It's not necessary that this is merged into v20-updates before #47 is merged. Just chose that as target branch so that the differences to main are more clearly visible.

[starry-shivam]

Hi, really thanks for taking your time to update this module, changes look good overall, I'll test it with real db in the evening and inform you.

[starry-shivam]

So i tested with actual db, apart from conversation related data everything seemed to work fine, was getting:

/data/data/com.termux/files/usr/lib/python3.10/site-packages/telegram/ext/_dictpersistence.py", line 170, in init
    raise TypeError(
TypeError: Unable to deserialize conversations_json. Not valid JSON

When loading conversation data, here is how data looks like in db for reference:

{"chat_data": "{\"894380120\": {}}", "user_da
ta": "{\"894380120\": {}}", "bot_data": "{}",
"conversations": "null", "callback_data": "[[]
, {}]"}
(1 row)

I think here in line 474 of dictpersistence when it does json.loads("null") it evaluates to None and ofcourse NoneType object don't have any .items() attribute it raises this error at line 169 of dictpersistence. BTW adding conversations_json = data.get("conversations", "{}") at line 85 seems to fix the issue. Also i think _key_maper() function is not used anywhere now, so it's better to remove that.

[Bibo-Joshi]

Thanks for testing 💪 The fix makes sense - just pushed it. If you could double check with the fix, that would be awesome :)

[starry-shivam]

Sure! Will do it in morning.

[starry-shivam]

Tested again, everything seems to work fine.

[Bibo-Joshi]

Thanks again for testing :)