code: def from_pypirc(pypi_repository):
      
      ret = {}
      pypirc_locations = PYPIRC_LOCATIONS
      for pypirc_path in pypirc_locations:
          pypirc_path = os.path.expanduser(pypirc_path)
          if os.path.isfile(pypirc_path):
              parser = configparser.SafeConfigParser()
              parser.read(pypirc_path)
              if 'distutils' not in parser.sections():
                  continue
              if 'index-servers' not in parser.options('distutils'):
                  continue
              if pypi_repository not in parser.get('distutils', 'index-servers'):
                  continue
              if pypi_repository in parser.sections():
                  for option in parser.options(pypi_repository):
                      ret[option] = parser.get(pypi_repository, option)
      if not ret:
          raise ConfigError(
              'repository does not appear to be configured in pypirc ({})'.format(pypi_repository) +
              ', remember that it needs an entry in [distutils] and its own section'
          )
      return ret
docs: Load configuration from .pypirc file, cached to only run once