python中的replace函数给出了错误的结果

干膜厚度:

    Sample  AlmostFinal  
    1          KOPLA234        
    1          KOPLA234
    2          RWPLB253
    3          MMPLA415
    3          MMPLA415 

KOPL 和 RWP MM 到Kolpol,最后一个字符a/b应保留。所以结果应该是:

    Sample  AlmostFinal  Final
    1          KOPLA234  KOLPOLA234      
    1          KOPLA234  KOLPOLA234
    2          RWPLB253  KOLPOLB253
    3          MMPLA415  KOLPOLA415
    3          MMPLA415  KOLPOLA415

    dfF['Final'] = (dfF['AlmostFinal'].replace({'KOPL':'KOLPOL'}, regex = True))
    dfF['Final'] = (dfF['AlmostFinal'].replace({'RWP':'KOLPOL'}, regex = True))
    dfF['Final'] = (dfF['AlmostFinal'].replace({'MMPL':'KOLPOL'}, regex = True))

并且:如果我评论第2行和第3行代替了Kopl的工作。