将numpy数组分配给pandas数据帧的特定单元格

import pandas as pd
import numpy as np

# 创建一个空的数据帧
df = pd.DataFrame()

# 创建一个3x3的numpy数组
arr = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])

# 将numpy数组分配给数据帧的特定单元格
df.at[0, 'A'] = arr[0, 0]
df.at[0, 'B'] = arr[0, 1]
df.at[0, 'C'] = arr[0, 2]
df.at[1, 'A'] = arr[1, 0]
df.at[1, 'B'] = arr[1, 1]
df.at[1, 'C'] = arr[1, 2]
df.at[2, 'A'] = arr[2, 0]
df.at[2, 'B'] = arr[2, 1]
df.at[2, 'C'] = arr[2, 2]

# 打印数据帧
print(df)

     A    B    C
0  1.0  2.0  3.0
1  4.0  5.0  6.0
2  7.0  8.0  9.0