Store list in dataframe R

At times, you may need to convert Pandas DataFrame into a list in Python.

But how would you do that?

To accomplish this task, you can use tolist as follows:

df.values.tolist[]

In this short guide, you’ll see an example of using tolist to convert Pandas DataFrame into a list.

Example of using tolist to Convert Pandas DataFrame into a List

Let’s say that you have the following data about products and prices:

product	price
Tablet	250
Printer	100
Laptop	1200
Monitor	300

You then decided to capture that data in Python using Pandas DataFrame.

At a certain point, you realize that you’d like to convert that Pandas DataFrame into a list.

To accomplish this goal, you may use the following Python code in order to convert the DataFrame into a list, where:

• The top part of the code, contains the syntax to create the DataFrame with our data about products and prices
• The bottom part of the code converts the DataFrame into a list using: df.values.tolist[]

Here is the full Python code:

import pandas as pd data = {'product': ['Tablet','Printer','Laptop','Monitor'], 'price': [250,100,1200,300] } df = pd.DataFrame[data] products_list = df.values.tolist[] print[products_list]

And once you run the code, you’ll get the following multi-dimensional list [i.e., list of lists]:

[['Tablet', 250], ['Printer', 100], ['Laptop', 1200], ['Monitor', 300]]

Optionally, you may further confirm that you got a list by adding print[type[products_list]] at the bottom of the code:

import pandas as pd data = {'product': ['Tablet','Printer','Laptop','Monitor'], 'price': [250,100,1200,300] } df = pd.DataFrame[data] products_list = df.values.tolist[] print[products_list] print[type[products_list]]

As you can see, the original DataFrame was indeed converted into a list [as highlighted in yellow]:

[['Tablet', 250], ['Printer', 100], ['Laptop', 1200], ['Monitor', 300]]

Convert an Individual Column in the DataFrame into a List

Let’s say that you’d like to convert the ‘product‘ column into a list.

You can then use the following template in order to convert an individual column in the DataFrame into a list:

df['column_name'].values.tolist[]

Here is the complete Python code to convert the ‘product’ column into a list:

import pandas as pd data = {'product': ['Tablet','Printer','Laptop','Monitor'], 'price': [250,100,1200,300] } df = pd.DataFrame[data] product = df['product'].values.tolist[] print[product]

Run the code, and you’ll get the following list:

['Tablet', 'Printer', 'Laptop', 'Monitor']

What if you want to append an additional item [e.g., Keyboard] into the ‘product’ list?

In that case, simply add the following syntax:

product.append['Keyboard']

So the complete Python code would look like this:

import pandas as pd data = {'product': ['Tablet','Printer','Laptop','Monitor'], 'price': [250,100,1200,300] } df = pd.DataFrame[data] product = df['product'].values.tolist[] product.append['Keyboard'] print[product]

You’ll now see the ‘Keyboard’ at the end of the list:

['Tablet', 'Printer', 'Laptop', 'Monitor', 'Keyboard']

An Opposite Scenario

Sometimes, you may face an opposite situation, where you’ll need to convert a list to a DataFrame. If that’s the case, you may want to check the following guide that explains how to convert a list to a DataFrame in Python.

# Add a list to data.frame in single 'element' slot # 1] Make data.frame from named list [names are optional] rowA