def install_requirements(self, path, index=None):
        """Install packages from a requirements.txt file.

        Args:
            path (str): The path to the requirements file.
            index (str): The URL for a pypi index to use.
        """
        cmd = 'install -r {0}'.format(path)
        if index:

            cmd = 'install --index-url {0} -r {1}'.format(index, path)

        self.pip(cmd)
def install_requirements ( self , path , index = None ) : cmd = 'install -r {0}' . format ( path ) if index : cmd = 'install --index-url {0} -r {1}' . format ( index , path ) self . pip ( cmd )
Install packages from a requirements.txt file.

        Args:
            path (str): The path to the requirements file.
            index (str): The URL for a pypi index to use.