How to Add an Empty Column to a Pandas DataFrame


Occasionally you may want to add an empty column to a pandas DataFrame.

Fortunately this is fairly easy to do and this tutorial shows several examples of how to do so using the following pandas DataFrame:

import numpy as np
import pandas as pd

#create DataFrame
df = pd.DataFrame({'points': [25, 12, 15, 14, 19],
                   'assists': [5, 7, 7, 9, 12],
                   'rebounds': [11, 8, 10, 6, 6]})

#view DataFrame
df

	points	assists	rebounds
0	25	5	11
1	12	7	8
2	15	7	10
3	14	9	6
4	19	12	6

Example 1: Add an Empty Column Using “”

The first way to add an empty column is to use quotations as follows:

#add new column titled 'steals' 
df['steals'] = ""

#view DataFrame
df

	points	assists	rebounds steals
0	25	5	11	
1	12	7	8	
2	15	7	10	
3	14	9	6	
4	19	12	6	

Example 2: Add an Empty Column Using Numpy

Another way to add an empty column is to use np.nan as follows:

#add new column titled 'steals'
df['steals'] = np.nan

#view DataFrame
df

        points	assists	rebounds steals
0	25	5	11	 NaN
1	12	7	8	 NaN
2	15	7	10	 NaN
3	14	9	6	 NaN
4	19	12	6	 NaN

Example 3: Add an Empty Column Using Pandas Series

Another way to add an empty column is to use pd.Series() as follows:

#add new column titled 'steals'
df['steals'] = pd.Series()

#view DataFrame
df

        points	assists	rebounds steals
0	25	5	11	 NaN
1	12	7	8	 NaN
2	15	7	10	 NaN
3	14	9	6	 NaN
4	19	12	6	 NaN

Example 4: Add an Empty Column Using Pandas Insert

Another way to add an empty column is to use the insert() function as follows:

#create DataFrame
df = pd.DataFrame({'points': [25, 12, 15, 14, 19],
                   'assists': [5, 7, 7, 9, 12],
                   'rebounds': [11, 8, 10, 6, 6]})

#insert empty column titled 'steals' into index position 2
df.insert(2, "steals", np.nan)

#view DataFrame
df

	points	assists	steals	rebounds
0	25	5	NaN	11
1	12	7	NaN	8
2	15	7	NaN	10
3	14	9	NaN	6
4	19	12	NaN	6

The nice part about this approach is that you can insert the empty column into any position you’d like in the DataFrame.

Example 5: Add Multiple Empty Columns at Once

To add multiple empty columns at once, you can use the reindex() function as follows:

#create DataFrame
df = pd.DataFrame({'points': [25, 12, 15, 14, 19],
                   'assists': [5, 7, 7, 9, 12],
                   'rebounds': [11, 8, 10, 6, 6]})

#add empty columns titled 'empty1' and 'empty2'
df = df.reindex(columns = df.columns.tolist() + ['empty1', 'empty2'])

#view DataFrame
df

        points	assists	rebounds empty1	empty2
0	25	5	11	 NaN	NaN
1	12	7	8	 NaN	NaN
2	15	7	10	 NaN	NaN
3	14	9	6	 NaN	NaN
4	19	12	6	 NaN	NaN

You can find more Python tutorials here.

Leave a Reply

Your email address will not be published.