计算一个值出现在 dataframe 列末尾的频率 [英]count the frequency that a value occurs in the end of a dataframe column
计算pandas列中值的频率,其中另一列中的值相似 [英]Count frequency of value in pandas column where values in another column are similar
当频率小于3时,如何进行逐列计数和更改值? [英]How can I do column wise counts and change value when the frequency is less than 3?