DataFrame 填充空列

直接赋值给新列名的列即可，

例如，以下示例中，原来有三列A，B，C，需要加上一列D，D列的值都是’ColumnD’。

示例代码：

import pandas as pd

filepath = 'H:\\TestPYTHON\\datapub.csv'

dataheader = ['A','B','C']

data_original = pd.read_csv(filepath, sep=',', header=0, names=dataheader, skip_blank_lines=True)

print data_original

data_original['D']='ColumnD'

print data_original

结果如下：

In [4]: %run "H:\TestPYTHON\public.py"
    A   B  C
0  a1  b1  1
1  a2  b2  2
2  a3  b3  3
    A   B  C        D
0  a1  b1  1  ColumnD
1  a2  b2  2  ColumnD
2  a3  b3  3  ColumnD

自我实践：

import pandas as pd
import numpy as np
dataheader = ['A','B','C']
a = np.arange(12).reshape(4,3)
print ('a',a)
df = pd.DataFrame(a,columns=[dataheader])


print (df)

df['D']='a'
print (df)
re = [2,3,4,5]
df['C'] = re
print(df)