Get a list of a specified column of a Pandas DataFrame

In this article, we will discuss how to get a list of specified column of a Pandas Dataframe. First, we will read a csv file into a pandas dataframe. 

Note: To get the CSV file used click here.

Creating the DataFrame

Python3

# importing pandas module
import pandas as pd

# making data frame from csv
data = pd.read_csv("nba.csv")

# calling head() method
df = data.head(5)

# displaying data
df

Output:

Get a list of a specified column of a Pandas

Let’s see how to get a list of a specified column of a Pandas DataFrame:
We will convert the column “Name” into a list. 

Using series.tolist() to get a list of a specified column

From the dataframe, we select the column “Name” using a [] operator that returns a Series object. Next, we will use the function Series.to_list() provided by the Series class to convert the series object and return a list.

Python3

# importing pandas module
import pandas as pd

# making data frame from csv
data = pd.read_csv("nba.csv")
df = data.head(5)

# Converting a specific Dataframe
# column to list using Series.tolist()
Name_list = df["Name"].tolist()

print("Converting name to list:")

# displaying list
Name_list

Output:

Get a list of a specified column of a Pandas

Let’s break it down and look at the types 

Python3

# column 'Name' as series object
print(type(df["Name"]))

# Convert series object to a list
print(type(df["Name"].values.tolist()

Output:

Get a list of a specified column of a Pandas

Using numpy.ndarray.tolist() to get a list of a specified column

With the help of numpy.ndarray.tolist(), dataframe we select the column “Name” using a [] operator that returns a Series object and uses Series.Values to get a NumPy array from the series object. Next, we will use the function tolist() provided by NumPy array to convert it to a list.

Python3

# Converting a specific Dataframe column
# to list using numpy.ndarray.tolist()
Name_list = df["Name"].values.tolist()

print("Converting name to list:")

# displaying list
Name_list

Output:

Get a list of a specified column of a Pandas

Similarly, breaking it down 

Python3

# Select a column from dataframe
# as series and get a numpy array
print(type(df["Name"].values))

# Convert numpy array to a list
print(type(df["Name"].values.tolist()

Output:

Get a list of a specified column of a Pandas

Using Python list() function to get a list of a specified column

You can also use the Python list() function with an optional iterable parameter to convert a column into a list.

Python3

Name_List = list(df["Name"])

print("Converting name to list:")

# displaying list
Name_List

Output:

Get a list of a specified column of a Pandas

Converting index column to list

Index column can be converted to list, by calling pandas.DataFrame.index which returns the index column as an array and then calling index_column.tolist() which converts index_column into a list. 

Python3

# Converting index column to list
index_list = df.index.tolist()

print("Converting index to list:")

# display index as list
index_list

Output:

Get a list of a specified column of a Pandas