Como resolver ImportError: Nenhum módulo chamado certifi

Estou usando o Debian Testing e estou tentando instalar dois módulos, um deles é o cliente de discog. No entanto, eu continuo acertando essa coisa certifi que eu não tenho iodea.

De acordo com a minha instalação python, o módulo certifi está no sistema . Veja as linhas abaixo.

python

Python 2.7.15 (default, May  1 2018, 05:55:50) 
[GCC 7.3.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import certifi
>>> certifi.where()
'/etc/ssl/certs/ca-certificates.crt'

Aqui está o erro.

pip install discogs-client

File "/usr/local/bin/pip", line 7, in <module>
    from pip._internal import main
  File "/usr/local/lib/python2.7/dist-packages/pip/_internal/__init__.py", line 42, in <module>
    from pip._internal import cmdoptions
  File "/usr/local/lib/python2.7/dist-packages/pip/_internal/cmdoptions.py", line 16, in <module>
    from pip._internal.index import (
  File "/usr/local/lib/python2.7/dist-packages/pip/_internal/index.py", line 15, in <module>
    from pip._vendor import html5lib, requests, six
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/requests/__init__.py", line 99, in <module>
    from . import utils
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/requests/utils.py", line 24, in <module>
    from . import certs
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/requests/certs.py", line 15, in <module>
    from pip._vendor.certifi import where
ImportError: No module named certifi

Aqui está o pip install certifi

pip install certifi
Traceback (most recent call last):
  File "/usr/local/bin/pip", line 7, in <module>
    from pip._internal import main
  File "/usr/local/lib/python2.7/dist-packages/pip/_internal/__init__.py", line 42, in <module>
    from pip._internal import cmdoptions
  File "/usr/local/lib/python2.7/dist-packages/pip/_internal/cmdoptions.py", line 16, in <module>
    from pip._internal.index import (
  File "/usr/local/lib/python2.7/dist-packages/pip/_internal/index.py", line 15, in <module>
    from pip._vendor import html5lib, requests, six
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/requests/__init__.py", line 99, in <module>
    from . import utils
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/requests/utils.py", line 24, in <module>
    from . import certs
  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/requests/certs.py", line 15, in <module>
    from pip._vendor.certifi import where
ImportError: No module named certifi