整理 - df = df[["A","B"]] - 重排列

import numpy as np
import pandas as pd
df = pd.DataFrame(data=[{"A":"1", "B":"3","C":"6"}, {"A":"3", "B":"2","C":"6"}, {"A":"2", "B":"1","C":"6"}])
df = pd.DataFrame(data=[{"A":1, "B":3,"C":6}, {"A":3, "B":2,"C":6}, {"A":2, "B":1,"C":6}])

order = ['B', 'A']
df = df[order]

可以看见列顺序根据order排列了，没有选择的列并没有显示