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Get a list of a specified column of a Pandas DataFrame

  • Difficulty Level : Basic
  • Last Updated : 28 Jul, 2020
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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:

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