Don't raise with the Exception class

[edmondchuc]

In a few places in deta/base.py exceptions are raised with the Exception class.

See https://github.com/deta/deta-python/blob/5e68173ffea4b3dd2c3d75fadda4e3c9854d3199/deta/base.py.

deta-python/deta/base.py

Line 134 in 5e68173

raise Exception("Item with key '{4}' already exists".format(key))

deta-python/deta/base.py

Line 272 in 5e68173

raise Exception("Key '{}' not found".format(key))

It'd be better practice if custom exceptions were defined and derived from the general Exception class.

[saadmanrafat]

Using Built-in Exceptions would be ideal than writing custom Exceptions. Simple solution would be to use the built-in KeyError Exception. Refactoring the codebase with Custom Exceptions might make it harder for the maintainers, who have their own flow -- just something to think about before creating a PR.

[abdelhai]

hi @edmondchuc, does PR #69 solve this issue for you?