python基础，dateframe修改值

python基础，dateframe修改值

#!/usr/bin/env python3
#  -*- coding: utf-8 -*-
# 程序开发：李庚锴 vx：1985159637
__author__ = 'ligengkai'
import numpy as np
import pandas as pd
arr=np.ones([2,3])
# print(arr,'n')
# df=pd.DataFrame(arr,index=['第一行','第二行'],columns=['a','b','c'])
# print(df)
df=pd.DataFrame(arr, columns=['a','b','c'])
print(df)
print('======')
df['d']=0
print(df)
print('======')
df.loc[1,'d']=5
print(df)
'''
运行结果：
     a    b    c
0  1.0  1.0  1.0
1  1.0  1.0  1.0
======
     a    b    c  d
0  1.0  1.0  1.0  0
1  1.0  1.0  1.0  0
======
     a    b    c  d
0  1.0  1.0  1.0  0
1  1.0  1.0  1.0  5
'''