Fixed file format based on coding standards
Moved late imports, fixed whitespace issues, cleaned up comments.
Hello @ranOutaNames! Thanks for opening this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:

* In the file [`pandas/core/arrays/integer.py`](https://github.com/pandas-dev/pandas/blob/2d0fcc21cc5e5b8a8f1848800eef47aa5f047f80/pandas/core/arrays/integer.py):

> [Line 468:13](https://github.com/pandas-dev/pandas/blob/2d0fcc21cc5e5b8a8f1848800eef47aa5f047f80/pandas/core/arrays/integer.py#L468): [E125](https://duckduckgo.com/?q=pep8%20E125) continuation line with same indent as next logical line

 > Moved late imports, fixed whitespace issues, cleaned up comments.

Did you run the tests locally after making these changes? Usually imports done not at the top of the file are because of circular import issues.

Also, the whitespace is a purposeful style choice to separate sections following isort (https://github.com/PyCQA/isort) Thanks for the PR @ranOutaNames. 

As mentioned, these runtime imports are meant to avoid circular imports so they cannot be changed (easily).

Going to close this PR, but happy to have your help on other issues in the pandas tracker, especially ones labeled "good first issue"  