your proposed patch is certainly wrong. You need to find out why these references aren't resolved by the python-pip-whl package.
- Bug#896998: python-pip: missing required _vendor module... Paul Gevers
- Bug#896998: python-pip: missing required _vendor m... Nicholas D Steeves
- Bug#896998: python-pip: missing required _vend... Nicholas D Steeves
- Bug#896998: [patch v2] Re: python-pip: missing req... Nicholas D Steeves
- Bug#896998: [patch v3] Re: python-pip: missing req... Nicholas D Steeves
- Bug#896998: closed by Matthias Klose <d...@debi... Nicholas D Steeves
- Bug#896998: Not fixed in python-pip 9.0.1-2.2 Nicholas D Steeves
- Bug#896998: python-pip: missing required _vendor m... Matthias Klose
