def install_requirements(self):
        print('\nStep 2. Install requirements')

        # Install requirements from necessary requirements file
        if os.path.isfile(self.requirements_file):
            args = ['install',
                    '-E', os.path.basename(self.dest_dir),
                    '-r', os.path.basename(self.requirements_file)]

            if CONFIG['pip']['download_cache']:
                download_cache = \
                    self.template_context % CONFIG['pip']['download_cache']
                args.extend(['--download-cache', download_cache])

            for name in ('quiet', 'upgrade', 'verbose'):
                if CONFIG['pip'][name]:
                    args.append('--' + name)

            try:
                pip.main(args)
            except SystemExit, e:
                if e.code:
                    raise e
        else:
            print('ERROR: Cannot to find requirements file at %r.' % \
                  self.requirements_file)
            sys.exit(1)
dataset/ETHPy150Open playpauseandstop/tddspry/tests/bootstrap.py/Environment.install_requirements/swapped operands of `%`