def _GetShowID(self, showName):
    """
    Get epguides show id for a given show name.

    Attempts to match the given show name against a show title in
    self._showTitleList and, if found, returns the corresponding index
    in self._showIDList.

    Parameters
    ----------
      showName : string
        Show name to get show ID for.

    Returns
    ----------
      int or None
        If a show id is found this will be returned, otherwise None is returned.
    """
    self._GetTitleList()
    self._GetIDList()

    for index, showTitle in enumerate(self._showTitleList):
      if showName == showTitle:
        return self._showIDList[index]
    return None