import re


def remove_punctuation(line):
    """
    去除所有半角全角符号，只留字母、数字、中文
    :param line:
    :return:
    """
    rule = re.compile(u"[^a-zA-Z0-9\u4e00-\u9fa5]")
    line = rule.sub('', line)
    return line