pandas 用另一列替换一部分列 [英] pandas replace part of a column with another column

问题描述

所以我有一个pandas数据框，我们称它为data；数据有两列，列a和列b.就像这样:

So i have a pandas data frame, let's call it data;data has two columns,column a and column b.Like this:

  a          b
0 aaa        tts
1 abb        tst
2 aba        tss

我想用b列替换a列中的每个"a".像这样:

I would like to replace each "a" in column a with column b.Like this:

  a          b
0 ttsttstts tts
1 tstbb      tst
2 tssbtss    tss

我绑了这样的东西:

data['a'] = data['a'].apply(lambda x:x.replace("sub-string",data['b']))

但是我除外，没有工作.有人可以告诉我该怎么做.

but as i excepted,did not work.could anyone please tell me what to do.

推荐答案

您需要在df上逐行迭代(传递axis=1)，以便可以访问要替换的各个"b"列值第一栏中所有出现的"a":

You need to iterate row-wise on the df (passing axis=1) so that you can access the individual 'b' column values that you intend to replace all occurrences of 'a' in the first column:

In [51]:
df['a'] = df.apply(lambda x: x['a'].replace('a',x['b']), axis=1)
df

Out[51]:
           a    b
0  ttsttstts  tts
1      tstbb  tst
2    tssbtss  tss

这篇关于 pandas 用另一列替换一部分列的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！