将 DataFrame 附加为新列

Question

I have the following piece of code:

rev = input(rev: )
def ds():
    data = pd.read_excel(r'H:\sysfile.xls', skiprows=2)
    dataset1 = pd.DataFrame(data, columns=['Col_1', 'Col_2', 'Col_3', 'Col_4'])
    dataset2 = pd.DataFrame(data, columns=['Col_5'])
    dataset2['Col_5'] = dataset2['Col_5'].fillna(rev)

ds()

Col_5 is an existing Column in the xls File. I want to give every cell in the column the input from rev If I print() the dataset1 i get the content of the existing DataFrame (read from the xls -File):

   A    B    C
0  x    y    z
1  x    y    z
2  x    y    z

Now I want to write the userinput from rev=input() into DataFrame dataset2 and append it to dataset 1 .

INPUT:

>>>rev: h

Should become this ( dataset2 ):

    D
0   h
1   h
2   h

and appand to dataset1 :

   A    B    C    D
0  x    y    z    h
1  x    y    z    h
2  x    y    z    h

I need help!

Answer 1

You can get Transpose of your data frame and add that column as a row.

After adding that row you can use Transpose again to transform your data frame to its normal form

Answer 2

If you managed already to fill the dataset2 with the user input, what you need is to join both datasets:

dataset1 = pd.DataFrame({'A': ['X', 'X', 'X', 'X'], 'B': ['Y', 'Y', 'Y', 'Y'], 'C': ['z', 'z', 'z', 'z']})

Out[5]: 
   A  B  C
0  X  Y  z
1  X  Y  z
2  X  Y  z
3  X  Y  z

dataset2 = pd.DataFrame({'D': ['h', 'h', 'h', 'h']})

Out[8]: 
   D
0  h
1  h
2  h
3  h

At this point you need to join them:

result = pd.concat([df1, df2], axis=1, sort=False)

Out[10]: 
   A  B  C  D
0  X  Y  z  h
1  X  Y  z  h
2  X  Y  z  h
3  X  Y  z  h

You can read it in here for further details: https://pandas.pydata.org/pandas-docs/stable/user_guide/merging.html