迭代Pandas DataFrame与迭代它的列名是一样的吗？

import pandas as pd

data = {'A': [1, 2, 3], 'B': [4, 5, 6], 'C': [7, 8, 9]}
df = pd.DataFrame(data)

for column in df:
    print(column)

A
B
C

for index, row in df.iterrows():
    print(index, row)

0 A    1
  B    4
  C    7
1 A    2
  B    5
  C    8
2 A    3
  B    6
  C    9

for column in df.columns:
    print(column)

A
B
C