如何将多标签数据集拆分为多行,每行有一个标签?

numpy.repeat Series.str.len 并按 chain.from_iterable :

from itertools import chain

df = pd.DataFrame({
    'Feature' : df['Feature'].values.repeat(df['Class'].str.len()),
    'Class' : list(chain.from_iterable(df['Class'].values.tolist()))
})
print (df)
  Feature   Class
0   text1  label1
1   text1  label2
2   text2  label2
3   text2  label3