如何子集R中的下一列

import pandas as pd

# 示例DataFrame
data = {
    'column_A': [1, 2, 3],
    'column_B': [4, 5, 6],
    'column_C': [7, 8, 9]
}
df = pd.DataFrame(data)

# 获取'column_A'之后的下一列
next_column = df.columns[df.columns.get_loc('column_A') + 1]

print(next_column)

if 'column_A' in df.columns:
    next_column = df.columns[df.columns.get_loc('column_A') + 1]
else:
    print("列 'column_A' 不存在")

if df.columns.get_loc('column_A') < len(df.columns) - 1:
    next_column = df.columns[df.columns.get_loc('column_A') + 1]
else:
    print("已经是最后一列")