code: def get_file_extension(filepath):
      
      _ext = os.path.splitext(filepath)[-1]
      if _ext:
          return _ext[1:] if _ext.startswith('.') else _ext
  
      return ''
docs: Copy if anyconfig.utils.get_file_extension is not available.
  
      >>> get_file_extension("/a/b/c")
      ''
      >>> get_file_extension("/a/b.txt")
      'txt'
      >>> get_file_extension("/a/b/c.tar.xz")
      'xz'