Open-event-server: empty_string() needs a rewrite

[cclauss]

Describe the bug

https://github.com/fossasia/open-event-server/blob/development/app/api/helpers/utilities.py#L28-L34 is exceedingly convoluted, does __type(x)__ compares contrary to PEP8, and contains several logic errors. A code review of this function would be a worthwhile effort. Some __doctests__ would really be helpful here.

To Reproduce
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Expected behavior

Stacktrace

Additional details (please complete the following information):

• OS: [e.g. MacOS, Ubuntu, CentOS]
• Python Version [e.g. 3.5, 3.6]
• HEAD Commit hash [e.g. 4629c62]

Additional context

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[iamareebjamal]

Yup. it was created when Python 2 to 3 migration/compatibility was needed

There are no doctests, but I think it has some unit tests. If not, they'll be added

[iamareebjamal]

There are unit tests. The behaviour is flaky though. None should return True, it is returning False

https://github.com/fossasia/open-event-server/blob/ff408e557f6ff12e37e72a5201d110d589ce50e3/tests/all/integration/api/helpers/test_utilities.py#L32

[cclauss]

Perhaps add a few more tests for clarity:

self.assertTrue(string_empty('  '))  # <space><space>
self.assertTrue(string_empty(' ' * 20))  # <space> * 20
self.assertFalse(string_empty(0))  # an int
self.assertFalse(string_empty(0.0))  # a float
self.assertFalse(string_empty([]))  # a list
self.assertFalse(string_empty(False))  # a bool

[cclauss]

self.assertTrue(string_empty('\t  \n'))  # <tab><space><return>

[cclauss]

Does this codebase still support Python 2 or not?

[cclauss]

From README.md it looks like legacy Python can be dropped so:

def string_empty(value: str) -> bool:
    if isinstance(value, str):
        return not value.strip()
    return False

[iamareebjamal]

def string_empty(value: str) -> bool:
    return isinstance(value, str) and not value.strip()