Moving columns in Pandas DATA FRAME

Question

I read the data from the csv file in a data frame consisting of more than 25,000 rows and 15 columns, and I need to move all the rows (including the leftmost → index) one column to the right so that I get an empty index and the ability to fill it with integers. However, column names should remain in one place. So basically I need to move everything except the column names one place to the right.

I tried to reindex it, but got an error:

ValueError: cannot reindex from a duplicate axis 

Is there any way to do this?

Answer 1

In pandas, you can create a column on the right, unless you are connecting between two data files. Then you can arrange as you like.

 import pandas as pd df = pd.read_csv('data.csv', header=None, names = ['A','B','C']) print(df) ABC 0 1 2 3 1 4 5 6 2 7 8 9 3 10 11 12 df['D'] = pd.np.nan # this creates an empty series # and appends to the right print(df) ABCD 0 1 2 3 NaN 1 4 5 6 NaN 2 7 8 9 NaN 3 10 11 12 NaN df = df[['D','A','B','C']] # rearrange as you like print(df) DABC 0 NaN 1 2 3 1 NaN 4 5 6 2 NaN 7 8 9 3 NaN 10 11 12 

Answer 2

First I would add a new column using

 df['new'] = df.index 

than reading the column names of your data frame in a list with:

 colnames = df.columns.tolist() 

Then you can change them as you need, for example, change the order so that you get the last “new” column as the first and move the rest of the position to the right:

 colnames = colnames[-1:] + colnames[:-1] 

and reassign:

 df = df[colnames] 

Answer 3

 df = YourDataFrame col = "Your Column You Want To Move To The Start Of YourDataFrame" df = pd.concat([df[col],df.drop(col,axis=1)], axis=1)