pip install cartopy

Collecting cartopy
  Using cached Cartopy-0.13.0.tar.gz
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "/tmp/pip-build-_hya0obf/cartopy/setup.py", line 36, in <module>
        from Cython.Distutils import build_ext
    ImportError: No module named 'Cython'

    During handling of the above exception, another exception occurred:

    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-build-_hya0obf/cartopy/setup.py", line 38, in <module>
        raise ImportError('Cython 0.15.1+ is required to install cartopy.')
    ImportError: Cython 0.15.1+ is required to install cartopy.

pip install cython

pip install cartopy