old_contents: from os.path import dirname, join
  
  try:
      import setuptools  # noqa
  except ImportError:
      from ez_setup import use_setuptools
      use_setuptools()
  
  from setuptools import find_packages, setup
  
  version = open('version.txt').read()
  
  
  classifiers = [ 'Development Status :: 4 - Beta'
                , 'Environment :: Console'
                , 'Intended Audience :: Developers'
                , 'License :: OSI Approved :: MIT License'
                , 'Natural Language :: English'
                , 'Operating System :: OS Independent'
                , 'Programming Language :: Python :: 3.6'
                , 'Programming Language :: Python :: 3.7'
                , 'Programming Language :: Python :: 3.8'
                , 'Programming Language :: Python :: 3.9'
                , 'Programming Language :: Python :: Implementation :: CPython'
                , 'Topic :: Internet :: WWW/HTTP :: WSGI :: Application'
                 ]
  
  setup( author = 'Chad Whitacre et al.'
       , author_email = 'team@aspen.io'
       , classifiers = classifiers
       , description = ('Pando is a Python web framework. '
                        'Simplates are the main attraction.')
       , long_description=open(join(dirname(__file__), 'README.rst')).read()
       , name = 'pando'
       , packages = find_packages(exclude=['pando.tests', 'pando.tests.*'])
       , url = 'http://aspen.io/'
       , version = version
       , zip_safe = False
       , package_data = {'pando': ['www/*', 'configuration/mime.types']}
       , install_requires = open('requirements.txt').read()
       , tests_require = open('requirements_tests.txt').read()
        )
  
new_contents: from os.path import dirname, join
  
  try:
      import setuptools  # noqa
  except ImportError:
      from ez_setup import use_setuptools
      use_setuptools()
  
  from setuptools import find_packages, setup
  
  version = open('version.txt').read()
  
  
  classifiers = [ 'Development Status :: 4 - Beta'
                , 'Environment :: Console'
                , 'Intended Audience :: Developers'
                , 'License :: OSI Approved :: MIT License'
                , 'Natural Language :: English'
                , 'Operating System :: OS Independent'
                , 'Programming Language :: Python :: 3.6'
                , 'Programming Language :: Python :: 3.7'
                , 'Programming Language :: Python :: 3.8'
                , 'Programming Language :: Python :: 3.9'
                , 'Programming Language :: Python :: Implementation :: CPython'
                , 'Topic :: Internet :: WWW/HTTP :: WSGI :: Application'
                 ]
  
  setup( author = 'Chad Whitacre et al.'
       , author_email = 'team@aspen.io'
       , classifiers = classifiers
       , description = ('Pando is a Python web framework. '
                        'Simplates are the main attraction.')
       , long_description=open(join(dirname(__file__), 'README.rst')).read()
       , long_description_content_type='text/x-rst'
       , name = 'pando'
       , packages = find_packages(exclude=['pando.tests', 'pando.tests.*'])
       , url = 'http://aspen.io/'
       , version = version
       , zip_safe = False
       , package_data = {'pando': ['www/*', 'configuration/mime.types']}
       , install_requires = open('requirements.txt').read()
       , tests_require = open('requirements_tests.txt').read()
        )
  
subject: add `long_description_content_type` to `setup.py`