问题描述
我想按索引和列合并两个数据集.
I want to merge two datasets by indexes and columns.
我想合并整个数据集
df1 = pd.DataFrame([[1, 0, 0], [0, 2, 0], [0, 0, 3]],columns=[1, 2, 3]) df1 1 2 3 0 1 0 0 1 0 2 0 2 0 0 3 df2 = pd.DataFrame([[0, 0, 1], [0, 2, 0], [3, 0, 0]],columns=[1, 2, 3]) df2 1 2 3 0 0 0 1 1 0 2 0 2 3 0 0
我已经尝试过这段代码,但我得到了这个错误.我不明白为什么它将轴的大小显示为错误.
I have tried this code but I got this error. I can't get why it shows the size of axis as an error.
df_sum = pd.concat([df1, df2]) .groupby(df2.index)[df2.columns] .sum().reset_index() ValueError: Grouper and axis must be same length
这就是我预期的 df_sum 的输出
This was what I expected the output of df_sum
df_sum 1 2 3 0 1 0 1 1 0 4 0 2 3 0 3
推荐答案
你可以使用:df1.add(df2, fill_value=0).它会将 df2 添加到 df1 中,并且它会将 NAN 值替换为 0.
You can use :df1.add(df2, fill_value=0). It will add df2 into df1 also it will replace NAN value with 0.
>>> import numpy as np >>> import pandas as pd >>> df2 = pd.DataFrame([(10,9),(8,4),(7,np.nan)], columns=['a','b']) >>> df1 = pd.DataFrame([(1,2),(3,4),(5,6)], columns=['a','b']) >>> df1.add(df2, fill_value=0) a b 0 11 11.0 1 11 8.0 2 12 6.0