fix code quality issues

[withshubh]

Description

Hi :wave: I work at DeepSource, I ran DeepSource analysis on the forked copy of this repo and found some interesting code quality issues in the codebase, opening this PR so you can assess if our platform is right and helpful for you.

Summary of changes

• Removed unnecessary use of comprehension
• Used sys.exit() calls
• Convert string with anomalous backslash into a raw string
• Refactored unnecessary else / elif when if block has a return statement
• Added .deepsource.toml config to continuously analyze the repo

[withshubh]

Hi @bitsadmin :wave:

Please review this PR :sparkles: