pandas的DataFrame多行求和问题.

Question

开发环境 python 3.6 pandas 0.23.3 有一个DataFrame,如下表示: import pandas as pd arr = [[10,10,1],[22,24.2,1.1],[15,15,1],[9,8.1,0.9],[50,55,1.1]] df = pd.DataFrame(arr,columns=['volume','amount','price']) volume amount price 0 10 10.0 1.0 1 22 24.2 1.1 2 15 15.0 1.0 3 9 8.1 0.9 4 50 55.0 1.1 需要volume列每行累加的和,得出total列 volume amount price total 0 10 10.0 1.0 10.0 1 22 24.2 1.1 32.0 2 15 15.0 1.0 47.0 3 9 8.1 0.9 56.0 4 50 55.0 1.1 106.0 目前我的写法: for index in df.index: num = df[df.index < index]['volume'].sum() df.loc['total'] = num 求助各位大神,有没有更好的方法?

Answer 1

df['total'] = df['volume'].cumsum()