Pandas How to Convert Series to List with Example

You can convert a pandas Series to a list by using the .tolist() method, like my_series.tolist().

Examples

Inputpd.Series([1, 2, 3])

Output[1, 2, 3]

Inputpd.Series(['apple', 'banana', 'cherry'])

Output['apple', 'banana', 'cherry']

Inputpd.Series([])

Output[]

How to Think About It

To convert a pandas Series to a list, think of the Series as a column of data. You want to take all the values in that column and put them into a simple Python list. The Series has a built-in method called tolist() that does exactly this by extracting all values in order.

Algorithm

1

Get the pandas Series object you want to convert.

2

Call the <code>tolist()</code> method on the Series.

3

Return the resulting Python list.

Code

python

import pandas as pd

my_series = pd.Series([10, 20, 30])
my_list = my_series.tolist()
print(my_list)

Output

[10, 20, 30]

Dry Run

Let's trace converting pd.Series([10, 20, 30]) to a list.

1

Create Series

my_series = pd.Series([10, 20, 30]) creates a Series with values 10, 20, 30.

2

Convert to list

Calling my_series.tolist() extracts values into a list [10, 20, 30].

3

Print list

Printing the list shows [10, 20, 30].

Step	Series Values	List Output
1	[10, 20, 30]
2	[10, 20, 30]	[10, 20, 30]
3		[10, 20, 30]

Why This Works

Step 1: Series holds data

A pandas Series stores data in a one-dimensional labeled array.

Step 2: tolist() extracts values

The tolist() method extracts all values from the Series into a plain Python list.

Step 3: Result is a list

The output is a standard Python list that can be used anywhere lists are accepted.

Alternative Approaches

Using list() constructor

python

import pandas as pd
my_series = pd.Series([1, 2, 3])
my_list = list(my_series)
print(my_list)

This also converts the Series to a list but is less explicit than using <code>tolist()</code>.

Using .values attribute with list()

python

import pandas as pd
my_series = pd.Series([1, 2, 3])
my_list = list(my_series.values)
print(my_list)

This converts the underlying numpy array to a list; similar result but slightly more indirect.

Complexity: O(n) time, O(n) space

Time Complexity

Converting a Series to a list requires visiting each element once, so it takes linear time proportional to the number of elements.

Space Complexity

A new list is created to hold all elements, so space used is proportional to the number of elements.

Which Approach is Fastest?

Using tolist() is optimized and clear; using list() on the Series or its values is similar but less explicit.

Approach	Time	Space	Best For
Series.tolist()	O(n)	O(n)	Clear, idiomatic conversion
list(Series)	O(n)	O(n)	Quick conversion, less explicit
list(Series.values)	O(n)	O(n)	Converts underlying array, slightly indirect