[ python ] pandas学习笔记（八）axis参数

axis = 0 或者index是行，有单行、多行
axis = 1 或者columns是列，是单列、多列

import numpy as np
import pandas as pd

b = pd.DataFrame(
    np.arange(12).reshape(3, 4),
    columns=['A', 'B', 'C', 'D'],
    index=['a', 'b', 'c']
)

删除某列

b = b.drop('A', axis=1)

删除某行

b = b.drop('a', axis=0)

求行列均值

c = b.mean(axis=0)
c = b.mean(axis=1)

axis=0 ->

axis=1 ->


axis=0,理解为得到行的索引，只能对行处理，行内数据无法进行交互