ValueError: cannot reindex from a duplicate axis, for two columns of same dataframe

Question

I have the below mentioned data frame as df.

           A         B         C         D         E
0     sarang  1.138380 -0.383898 -0.444186 -0.383898
1    -1.1499 -0.469425 -1.455522 -0.789694 -1.455522
2  -0.688895 -0.737444 -0.238886 -0.602263 -0.238886
3   -1.02036  0.400622 -0.020911 -1.366732 -0.020911
4    1.97958 -1.252052 -0.977561 -0.111656 -0.977561
5  0.0802027 -0.290397  1.672563  0.371790  1.672563

I am trying to concat the column C and D, into a new column 'E' using :

df['E']  = pd.concat([df['C'], df['D']])

The error it gives me is :

ValueError: cannot reindex from a duplicate axis

Also I if use the ignore_index command,

df['E']  = pd.concat([df['C'], df['D']], ignore_index = True)

Then I get the below output, which I'm unable to understand at all.

           A         B         C         D         E
0     sarang  1.138380 -0.383898 -0.444186 -0.383898
1    -1.1499 -0.469425 -1.455522 -0.789694 -1.455522
2  -0.688895 -0.737444 -0.238886 -0.602263 -0.238886
3   -1.02036  0.400622 -0.020911 -1.366732 -0.020911
4    1.97958 -1.252052 -0.977561 -0.111656 -0.977561
5  0.0802027 -0.290397  1.672563  0.371790  1.672563

What should I do otherwise to get rid of the error.

i want the data to get concatenated as strings if inputs are string. — Sarang Manjrekar, Apr 17 '18 at 10:23
I think need `df['E'] = df['C'] + df['D']` if strings columns, else `df['E'] = df['C'].astype(str) + df['D'].astype(str)` — jezrael, Apr 17 '18 at 10:30

ValueError: cannot reindex from a duplicate axis, for two columns of same dataframe

0 Answers0