在进行文本分析、提取关键词时，新闻评论等文本通常是中英文及其他语言的混杂，若不加处理直接分析，结果往往差强人意。
下面对中英文文本进行分离做一下总结：
1、超短文本，ASCII识别。
s = "China's Legend Holdings will split its several business arms to go public on stock markets, the group's president Zhu Linan said on Tuesday.该集团总裁朱利安周二表示，中国联想控股将分拆其多个业务部门在股市上市。" result = "".join(i for i in s if ord(i) < 256) print(result)
out: China's Legend Holdings will split its several business arms to go public on stock markets, the group's president Zhu Linan said on Tuesday.
2、unicode编码识别
import re s = "China's Legend Holdings will split its several business arms to go public on stock markets, the group's president Zhu Linan said on Tuesday.该集团总裁朱利安周二表示，中国联想控股将分拆其多个业务部门在股市上市。" uncn = re.compile(r'[\u0061-\u007a,\u0020]') en = "".join(uncn.findall(s.lower())) print(en)
out: chinas legend holdings will split its several business arms to go public on stock markets, the groups president zhu linan said on tuesday
中文的编码范围是：\u4e00-\u9fa5，相应的[^\u4e00-\u9fa5]可匹配非中文。
匹配英文时，需要将空格[\u0020]加入，不然单词之间没空格了。