old_contents: import pathlib
  import unittest
  from crc import LIBRARY_VERSION
  from setuptools import setup
  
  current = pathlib.Path(__file__).parent.resolve()
  
  
  def tests():
      return unittest.defaultTestLoader.discover(start_dir=f'{current.resolve()}', pattern='*test*.py')
  
  
  def readme():
      return (current / 'README.md').read_text(encoding='utf-8')
  
  
  if __name__ == '__main__':
      setup(
          name='crc',
          version=LIBRARY_VERSION,
          test_suite='setup.tests',
          py_modules=['crc'],
          classifiers=[
              'Programming Language :: Python :: 3.7',
              'Programming Language :: Python :: 3.8',
          ],
          url='https://github.com/Nicoretti/crc',
          license='BSD',
          author='Nicola Coretti',
          author_email='nico.coretti@gmail.com',
          description='Library and CLI to calculate and verify all kinds of CRC checksums.',
          keywords=['CRC', 'CRC8', 'CRC16', 'CRC32', 'CRC64'],
          long_description=readme(),
          long_description_content_type='text/markdown',
          entry_points={
              'console_scripts': [
                  'crc=crc:main',
              ],
          }
      )
  
new_contents: import pathlib
  import unittest
  from crc import LIBRARY_VERSION
  from setuptools import setup
  
  current = pathlib.Path(__file__).parent.resolve()
  
  
  def tests():
      return unittest.defaultTestLoader.discover(start_dir=f'{current.resolve()}', pattern='*test*.py')
  
  
  def readme():
      return (current / 'README.md').read_text(encoding='utf-8')
  
  
  if __name__ == '__main__':
      setup(
          name='crc',
          version=LIBRARY_VERSION,
          test_suite='setup.tests',
          py_modules=['crc'],
          classifiers=[
              'Programming Language :: Python :: 3.7',
              'Programming Language :: Python :: 3.8',
              'Programming Language :: Python :: 3.9',
          ],
          url='https://github.com/Nicoretti/crc',
          license='BSD',
          python_requires='>=3.7',
          author='Nicola Coretti',
          author_email='nico.coretti@gmail.com',
          description='Library and CLI to calculate and verify all kinds of CRC checksums.',
          keywords=['CRC', 'CRC8', 'CRC16', 'CRC32', 'CRC64'],
          long_description=readme(),
          long_description_content_type='text/markdown',
          entry_points={
              'console_scripts': [
                  'crc=crc:main',
              ],
          }
      )
  
subject: Add python_requires specifier to setup.py