python - Pandas :如何找到每行最频繁的值？

Question

如何找到数据帧每一行中出现频率最高的值？ 例如:

In [14]: df
Out[14]:
   a  b  c
0  2  3  3
1  1  1  2
2  7  7  8

返回: [3,1,7]

Answer 1

尝试 .mode()方法:

In [88]: df
Out[88]:
   a  b  c
0  2  3  3
1  1  1  2
2  7  7  8

In [89]: df.mode(axis=1)
Out[89]:
   0
0  3
1  1
2  7

来自文档:

Gets the mode(s) of each element along the axis selected. Adds a row for each mode per label, fills in gaps with nan.

Note that there could be multiple values returned for the selected axis (when more than one item share the maximum frequency), which is the reason why a dataframe is returned. If you want to impute missing values with the mode in a dataframe df, you can just do this: df.fillna(df.mode().iloc[0])