In DataFrames, Empty columns are defined and represented with NaN Value(Not a Number value or undefined or unrepresentable value). There are various methods to add Empty Column to Pandas Dataframe in Python.
Method 1: Add Empty Column to Dataframe using the Assignment Operator
We are using the assignment operator to assign empty strings to two newly created columns as “Gender” and “Department” respectively for Pandas Dataframes.
Python3
# import required librariesimport numpy as npimport pandas as pd# create a DataframeMydataframe = pd.DataFrame({'FirstName': ['Vipul', 'Ashish', 'Milan'], "Age": [21,22,23]})# show the dataframeprint("\n\n---Original Dataframe---\n", Mydataframe)# add an empty columnsMydataframe['Gender'] = ''Mydataframe['Department'] = ''# show the dataframeprint("---Updated Dataframe---\n", Mydataframe) |
Output:
Method 2: Add Empty Column to Dataframe using the np.nan
We are using np.nan values to two newly created columns as “Gender” and “Department” respectively for Pandas Dataframes(table). Numpy library is used to import NaN value and use its functionality.
Python3
# import required librariesimport numpy as npimport pandas as pd# show the dataframeprint("\n\n---Original Dataframe---\n", Mydataframe)# add an empty columnsMydataframe['Gender'] = np.nanMydataframe['Department'] = np.nan# show the dataframeprint("---Updated Dataframe---\n", Mydataframe) |
Output:
Method 3: Add Empty Column to Dataframe using the None
We are using None values to two newly created columns as “Gender” and “Department” respectively for Pandas Dataframes.
Python3
# import required librariesimport numpy as npimport pandas as pd# show the dataframeprint("\n\n---Original Dataframe---\n", Mydataframe)# add an empty columnsMydataframe['Gender'] = NoneMydataframe['Department'] = None# show the dataframeprint("---Updated Dataframe---\n", Mydataframe) |
Output:
Method 4: Add Empty Column to Dataframe using Dataframe.reindex().
We created a Dataframe with two columns “First name and “Age” and later used Dataframe.reindex() method to add two new columns “Gender” and ” Roll Number” to the list of columns with NaN values.
Python3
# import pandas libraryimport pandas as pd# create a dataframeMydataframe = pd.DataFrame({'FirstName': ['Preetika', 'Tanya', 'Akshita'], "Age": [25,21,22]})# show the dataframeprint("---Original Dataframe---\n", Mydataframe)# add an empty columnsMydataframe = Mydataframe.reindex(columns = Mydataframe.columns.tolist() + ['Gender','Roll Number'])# show the dataframeprint("\n\n---Updated Dataframe---\n", Mydataframe) |
Output:
Method 5: Add Empty Column to Dataframe using Dataframe.insert()
We are using the Dataframe.insert() method on pandas Dataframes to add an empty column “Roll Number”, here we can also insert the column at any index position we want (as here we placed the value at index location 0).
Python3
# import pandas libraryimport pandas as pd# create a dataframeMydataframe = pd.DataFrame({'FirstName': ['Rohan', 'Martin', 'Mary'], "Age": [28,39,21]})# show the dataframeprint("---Original Dataframe---\n", Mydataframe)# add an empty columnMydataframe.insert(0,'Roll Number','')# show the dataframeprint("\n\n---Updated Dataframe---\n", Mydataframe) |
Output:
