python - 如何找到列的 cumsum？

Question

dict={"asset":["S3","S2","E4","E1","A6","A8"],
"Rank":[1,2,3,4,5,6],"number_of_attributes":[2,1,2,2,1,1],
"number_of_cards":[1,2,2,1,2," "],"cards_plus1":[2,3,3,2,3," "]}

dframe=pd.DataFrame(dict,index=[1,2,3,4,5,6],
columns=["asset","Rank","number_of_attributes","number_of_cards","cards_plus1"])

我想对 "cards_plus1" 列进行 cumsum。我怎样才能做到这一点？列 cumsum 的输出应该是:02个5个8个1013

Answer 1

i want to start with zero instead of 2.. i want this outup : cards_plus1_cumsum 0 2 5 8 10 13

我们可以在求和前补一个零:

dframe["cumsum"] = np.pad(dframe["cards_plus1"][:-1].cumsum(), (1, 0), 'constant')