将列从一个数据帧添加到另一个python pandas

Question

我一直在网上搜索并发现了类似的问题，但仍无法找到我正在寻找的答案。 我有2个excel文件：

data1

ColumnA    columnB    columnC   columnD
  A          B          C          D
  A          B          C          D
  A          B          C          D

DATA2

ColumnE    columnF    columnG   
  E          F          G          
  E          F          G          
  E          F          G    

我想将data2中的列F添加到data1：

ColumnA    columnB    columnC   columnD  columnF 
  A          B          C          D       F
  A          B          C          D       F
  A          B          C          D       F

我试过

data2['columnF'] = data1['columnF']  #doesn't work

也尝试了

data1['columnF'] = ''   #adding a columnF to data1
merg_left = pd.merge(left=data1,right=data2, how='left',      
left_on='columnF', right_on='columnF')  
#gave me a weird output file 

Answer 1

import pandas as pd
import io

data = """
ColumnA    columnB    columnC   columnD
  A          B          C          D
  A          B          C          D
  A          B          C          D
    """
data1 = """
ColumnE    columnF    columnG
  E          F          G
  E          F          G
  E          F          G
    """

df = pd.read_csv(io.StringIO(data), delimiter='\s+')
df1 = pd.read_csv(io.StringIO(data1), delimiter='\s+')

df['columnF'] = pd.Series(df1['columnF'])

print(df)

会给你：

  ColumnA columnB columnC columnD columnF
0       A       B       C       D       F
1       A       B       C       D       F
2       A       B       C       D       F

Answer 2

import pandas as pd
f_column = data2["columnF"]
data1 = pd.concat([data1,f_column], axis = 1)
data1

     columnA      columnB     columnC     columnF
0       a            b            c         f
1       a            b            c         f
2       a            b            c         f

Answer 3

import pandas as pd

f_column = data2["columnF"] 

data1 = pd.concat([data1,f_column], axis = 1) 

data1

将提供所需的输出。