You can use the following methods to add empty columns to a pandas DataFrame:
Method 1: Add One Empty Column with Blanks
df['empty_column'] = ""
Method 2: Add One Empty Column with NaN Values
df['empty_column'] = np.nan
Method 3: Add Multiple Empty Columns with NaN Values
df[['empty1', 'empty2', 'empty3']] = np.nan
The following examples show how to use each method with the following pandas DataFrames:
import pandas as pd
#create DataFrame
df = pd.DataFrame({'team': ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H'],
'points': [18, 22, 19, 14, 14, 11, 20, 28],
'assists': [5, 7, 7, 9, 12, 9, 9, 4]})
#view DataFrame
print(df)
team points assists
0 A 18 5
1 B 22 7
2 C 19 7
3 D 14 9
4 E 14 12
5 F 11 9
6 G 20 9
7 H 28 4
Example 1: Add One Empty Column with Blanks
The following code shows how to add one empty column with all blank values:
#add empty column
df['blanks'] = ""
#view updated DataFrame
print(df)
team points assists blanks
0 A 18 5
1 B 22 7
2 C 19 7
3 D 14 9
4 E 14 12
5 F 11 9
6 G 20 9
7 H 28 4
The new column called blanks is filled with blank values.
Example 2: Add One Empty Column with NaN Values
The following code shows how to add one empty column with all NaN values:
import numpy as np
#add empty column with NaN values
df['empty'] = np.nan
#view updated DataFrame
print(df)
team points assists empty
0 A 18 5 NaN
1 B 22 7 NaN
2 C 19 7 NaN
3 D 14 9 NaN
4 E 14 12 NaN
5 F 11 9 NaN
6 G 20 9 NaN
7 H 28 4 NaN
The new column called empty is filled with NaN values.
Example 3: Add Multiple Empty Columns with NaN Values
The following code shows how to add multiple empty columns with all NaN values:
import numpy as np
#add three empty columns with NaN values
df[['empty1', 'empty2', 'empty3']] = np.nan
#view updated DataFrame
print(df)
team points assists empty1 empty2 empty3
0 A 18 5 NaN NaN NaN
1 B 22 7 NaN NaN NaN
2 C 19 7 NaN NaN NaN
3 D 14 9 NaN NaN NaN
4 E 14 12 NaN NaN NaN
5 F 11 9 NaN NaN NaN
6 G 20 9 NaN NaN NaN
7 H 28 4 NaN NaN NaN
Notice that all three of the new columns are filled with NaN values.
Additional Resources
The following tutorials explain how to perform other common tasks in pandas:
How to Rename Columns in Pandas
How to Add a Column to a Pandas DataFrame
How to Change the Order of Columns in Pandas DataFrame