df_paixu.iloc[df['start_index'][i_w]:(df['start_index'][i_w]+df['index_length'][i_w])] 实现什么功能

Question

这三行代码实现了啥功能啊

for i_w in range(df.shape[0]):
    df_scen=df_paixu.iloc[df['start_index'][i_w]:(df['start_index'][i_w]+df['index_length'][i_w])]     
    df_scen=df_scen.reset_index(drop=True)