How To Drop One or More Columns in Pandas Dataframe?

Often while working with a bigger pandas dataframe with multiple columns, one wants to drop one or more columns from a pandas dataframe.

How To Drop Columns in Pandas?

How To Drop Columns in Pandas?

One typically drops columns, if the columns are not needed for further analysis. Pandas drop function allows you to drop/remove one or more columns from a dataframe.

Let us see some examples of dropping or removing columns from a real world data set. Let us load pandas and load gapminder data from a URL.

import pandas as pd
gapminder = pd.read_csv(gapminder_url)

Let us do some filtering to make the dataframe smaller just for the ease of illustrating the examples of using drop function in Pandas. After filtering, we will have a smaller dataframe with just four rows and six columns.

gapminder_ocean = gapminder[(gapminder.year >2000) &
                            (gapminder.continent== 'Oceania')]

How To Drop a Single Column from a Dataframe?

To drop a single column from pandas dataframe, we need to provide the name of the column to be dropped as a list as an argument to drop function. Here, we have a list containing just one element, ‘pop’ variable. Pandas drop function can drop column or row. To specify we want to drop column, we need to provide axis=1 as another argument to drop function.

gapminder_ocean.drop(['pop'], axis=1)

The resulting dataframe will have just five columns instead of six. The column containing pop variable is removed now.

	country	year	continent	lifeExp	gdpPercap
70	Australia	2002	Oceania	80.370	30687.75473
71	Australia	2007	Oceania	81.235	34435.36744
1102	New Zealand	2002	Oceania	79.110	23189.80135
1103	New Zealand	2007	Oceania	80.204	25185.00911

How To Drop Multiple Columns from a Dataframe?

Pandas’ drop function can be used to drop multiple columns as well. To drop or remove multiple columns, one simply needs to give all the names of columns that we want to drop as a list. Here is an example with dropping three columns from gapminder dataframe.

gapminder_ocean.drop(['pop', 'gdpPercap', 'continent'], axis=1)

Note that now the resulting column contains just three columns instead of six columns.

country	year	lifeExp
70	Australia	2002	80.370
71	Australia	2007	81.235
1102	New Zealand	2002	79.110
1103	New Zealand	2007	80.204

How To Drop Specific Rows from a Dataframe?

Pandas make it easy to drop rows as well. We can use the same drop function. To drop one or few rows from a pandas dataframe, we need to specify the row indexes that need to be dropped and axis=0 argument. In this case, row indexes are numbers so we can create a list of row numbers to be dropped. Here, we have dropped rows corresponding to Australia.

	country	year	pop	continent	lifeExp	gdpPercap
1102	New Zealand	2002	3908037.0	Oceania	79.110	23189.80135
1103	New Zealand	2007	4115771.0	Oceania	80.204	25185.00911