python 错误：UnicodeEncodeError: 'ascii' codec can't encode character u'\xa0' in position

在python2.7下，将字符串写入到文件时会出现"UnicodeEncodeError: 'ascii' codec can't encode character u'\xa0' in position"的错误,原因是由于python基于ASCII处理字符的，当出现不属于ASCII的字符时，会出现错误信息。在python2.7下，将字符串写入到文件时会出现"UnicodeEncodeError