数据框列中的一组值的长度相同

Question

I would like to get the same lengtht for a group of values (0,1,2,3,4,5) in a column of a Data Frame. For example, I would like to reduce the amount of every group of values to the lowest exisiting (= 41)

input: train_df.relevancy.value_counts()

output:

output

Answer 1

IIUC use GroupBy.head by minimal value from Series.value_counts :

val = train_df.relevancy.value_counts().min()
train_df = train_df.groupby('relevancy').head(val)