Refactor

[sepandhaghighi]

Reference Issues/PRs

What does this implement/fix? Explain your changes.

• functions.py renamed to utils.py
• CLI functions moved to cli.py
• IPv4 functions moved to ipv4.py

Any other comments?

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.70%. Comparing base (9649fdc) to head (cd9dda4).

Additional details and impacted files

@@           Coverage Diff           @@
##              dev      #30   +/-   ##
=======================================
  Coverage   94.70%   94.70%           
=======================================
  Files           2        3    +1     
  Lines         151      151           
  Branches       15       15           
=======================================
  Hits          143      143           
  Misses          1        1           
  Partials        7        7           

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[sepandhaghighi]

@sadrasabouri

Please review this PR! 💯
Additionally, consider the following:

1. Test the CLI section manually
2. The is_loopback function is a general utility that also works with IPv6, so I moved it to utils.py.

[sadrasabouri]

It looks good, I also tested it locally on terminal and it's working as expected.