Skip segmentations of already processed subjects

What's Changed

• Avoid re-segmenting already processed subjects by @clementpoiret in #28
• refactor: refactor unnecessary else / elif when if block has a return statement by @deepsource-autofix in #29
• refactor: remove commented out code by @deepsource-autofix in #30
• refactor: remove assert statement from non-test files by @deepsource-autofix in #32
• style: format code with isort and Yapf by @deepsource-autofix in #31
• refactor: put docstring into a single line by @deepsource-autofix in #36
• refactor: remove blank lines after docstring by @deepsource-autofix in #35
• refactor: merge collapsible if statements by @deepsource-autofix in #34
• refactor: use identity check for comparison to a singleton by @deepsource-autofix in #33

New Contributors

• @deepsource-autofix made their first contribution in #29

Full Changelog: v1.2.0...v1.2.1