相关疑难解决方法(0)

我有一个Pandas Dataframe,如下所示:

    1    2       3
 0  a  NaN    read
 1  b    l  unread
 2  c  NaN    read

我想用空字符串删除NaN值,以便它看起来像这样:

    1    2       3
 0  a   ""    read
 1  b    l  unread
 2  c   ""    read