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.
Example:

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:

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 three different ways.
1. Using Series.tolist()
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:

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:

2. Using numpy.ndarray.tolist()
From the 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

# 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 numpy.ndarray.tolist() 
Name_list = df["Name"].values.tolist() 
  
print("Converting name to list:") 
  
# displaying list 
Name_list

Output:

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:

3. Using Python list() function
You can also use the Python list() function with an optional iterable parameter to convert a column into 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 list() 
# function in Python 
Name_List = list(df["Name"]) 
  
print("Converting name to list:") 
  
# displaying list 
Name_List

Output:

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:

My Personal Notes

Python3

Python3

Python3

Python3

Python3

Python3

Python3

Recommended Posts: