常用数据编辑-相加对齐

import pandas as pd
import numpy as np
np.random.seed(7)
df1 = pd.DataFrame(np.arange(20).reshape(5, 4), columns=['A', 'B', 'C', 'D'])
df2 = pd.DataFrame(np.arange(21).reshape(7, 3), columns=['A', 'B', 'C'])

data = df1.add(df2)
print('缺失值自动用NaN表示')
print(data)

data = df1.add(df2, fill_value=0)
print('缺失值填充0')
print(data)

print('缺失值填充矩阵均值,但是形状不同引起的缺失值还是不能消除')
fill1 = df1.stack().mean()
data = df1.add(df2, fill_value=fill1)
print(data)

fill2 = df1.mean()
print(fill2)