如何将一个数据帧的列值附加到另一个数据帧的列

Question

I'm working with 2 dataframes, A & B. Dataframe A is populated with values, while dataframe B is empty except for a header structure I want to take the value of column in dataframe A, and append them to the corresponding column in dataframe B.

I've placed the values of the dataframe A column I want to append in a list. I 've tried setting the destination column values to equal the list of start column values, but that gives me the following error:

dataframeB[x] = list(dataframeA[A])

This yields the following error:

ValueError: Length of values does not match length of index

The result I expect is Dataframe A's column A transfers over to Dataframe B's column x

  A  B  C  D  
  1  2  3  4  
  1  2  3  4  

Dataframe B

  x  y 
  -  -  

Answer 1

Create the dataframe with the data already in it...

dataframeB = pd.DataFrame(dataframeA['A'], columns = ['x'])

Then you can add columns in from the other dataframe:

dataframeB['y'] = dataframeA['B']

Result:

  x  y
  1  2 
  1  2