old_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  import os
  
  import jose
  
  import platform
  
  from setuptools import setup
  
  
  with open(os.path.join(os.path.dirname(__file__), 'README.rst')) as readme:
      long_description = readme.read()
  
  
  def get_packages(package):
      """
      Return root package and all sub-packages.
      """
      return [
          dirpath
          for dirpath, dirnames, filenames in os.walk(package)
          if os.path.exists(os.path.join(dirpath, '__init__.py'))
      ]
  
  
  def get_install_requires():
      if platform.python_implementation() == 'PyPy':
          crypto_lib = 'pycryptodome >=3.3.1, <3.4.0'
      else:
          crypto_lib = 'pycrypto >=2.6.0, <2.7.0'
      return [
          crypto_lib,
          'six <2.0',
          'ecdsa <1.0',
          'future <1.0',
      ]
  
  
  setup(
      name='python-jose',
      version=jose.__version__,
      author='Michael Davis',
      author_email='mike.philip.davis@gmail.com',
      description='JOSE implementation in Python',
      license='MIT',
      keywords='jose jws jwe jwt json web token security signing',
      url='http://github.com/mpdavis/python-jose',
      packages=get_packages('jose'),
      long_description=long_description,
      classifiers=[
          'Development Status :: 5 - Production/Stable',
          'Intended Audience :: Developers',
          'Natural Language :: English',
          'License :: OSI Approved :: MIT License',
          'Programming Language :: Python',
          'Programming Language :: Python :: 2.6',
          'Programming Language :: Python :: 2.7',
          'Programming Language :: Python :: 3.3',
          'Programming Language :: Python :: 3.4',
          'Programming Language :: Python :: 3.5',
          'Programming Language :: Python :: 3.6',
          'Programming Language :: Python :: Implementation :: PyPy',
          'Topic :: Utilities',
      ],
      install_requires=get_install_requires()
  )
  
new_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  import os
  
  import jose
  
  from setuptools import setup
  
  
  with open(os.path.join(os.path.dirname(__file__), 'README.rst')) as readme:
      long_description = readme.read()
  
  
  def get_packages(package):
      """
      Return root package and all sub-packages.
      """
      return [
          dirpath
          for dirpath, dirnames, filenames in os.walk(package)
          if os.path.exists(os.path.join(dirpath, '__init__.py'))
      ]
  
  
  extras_require = {
      'cryptography': ['cryptography'],
      'pycrypto': ['pycrypto >=2.6.0, <2.7.0'],
      'pycryptodome': ['pycryptodome >=3.3.1, <3.4.0'],
  }
  
  
  setup(
      name='python-jose',
      version=jose.__version__,
      author='Michael Davis',
      author_email='mike.philip.davis@gmail.com',
      description='JOSE implementation in Python',
      license='MIT',
      keywords='jose jws jwe jwt json web token security signing',
      url='http://github.com/mpdavis/python-jose',
      packages=get_packages('jose'),
      long_description=long_description,
      classifiers=[
          'Development Status :: 5 - Production/Stable',
          'Intended Audience :: Developers',
          'Natural Language :: English',
          'License :: OSI Approved :: MIT License',
          'Programming Language :: Python',
          'Programming Language :: Python :: 2.6',
          'Programming Language :: Python :: 2.7',
          'Programming Language :: Python :: 3.3',
          'Programming Language :: Python :: 3.4',
          'Programming Language :: Python :: 3.5',
          'Programming Language :: Python :: 3.6',
          'Programming Language :: Python :: Implementation :: PyPy',
          'Topic :: Utilities',
      ],
      extras_require=extras_require,
      install_requires=['six <2.0', 'ecdsa <1.0', 'future <1.0']
  )
  
subject: Implement optional backends for python-jose as setup.py extras. This allows installing running pip install python-jose[cryptography] to install with cryptography. Supported backends libraries are cryptography, pycrypto and cryptodome.