Read Only Certain Columns of CSV File as pandas DataFrame in Python (Example)

 

In this tutorial, I’ll illustrate how to import only some specific columns from a CSV file in the Python programming language.

The article will consist of the following information:

You’re here for the answer, so let’s get straight to the example!

 

Example Data & Add-On Libraries

First, we need to import the pandas library:

import pandas as pd                         # Load pandas library

The following data is used as a basis for this Python programming tutorial:

data = pd.DataFrame({'x1':range(14, 22),    # Create pandas DataFrame
                     'x2':[7, 3, 7, 5, 3, 9, 1, 8],
                     'x3':['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'],
                     'x4':[9, 2, 1, 1, 4, 1, 4, 8],
                     'x5':range(35, 27, - 1)})

As you can see, our example data set contains the five columns x1, x2, x3, x4, and x5.

We can export this data set to a CSV file using the to_csv function:

data.to_csv('data.csv')                     # Export pandas DataFrame

Once the previous Python syntax has been executed, a new CSV file containing our example data appears in our current working directory.

 

Example: Read Only Specific Columns from CSV File

The following Python programming syntax shows how to import only certain variables of a CSV file as a new pandas DataFrame in Python.

To accomplish this, we have to apply the read_csv function and the usecols argument as shown below. To the usecols argument, we have to assign a list of column names that we want to load:

data_import3 = pd.read_csv('data.csv',      # Read pandas DataFrame from CSV
                           usecols = ['x2', 'x4', 'x5'])
print(data_import3)                         # Print imported pandas DataFrame

 

table 1 DataFrame read only certain columns csv file as pandas dataframe python

 

Table 1 displays the Python console output and shows that we have created a new pandas DataFrame that contains eight rows and the three columns x2, x4, and x4.

The variables x1 and x3 from our input CSV have been ignored.

 

Video & Further Resources

Do you want to know more about the reading of particular variables from a CSV file as a pandas DataFrame? Then I recommend having a look at the following video on my YouTube channel. In the video, I show the Python syntax of this tutorial in a live programming session:

 

The YouTube video will be added soon.

 

In addition, you might read some of the other tutorials on this website:

 

You have learned in this tutorial how to load only some specific columns from a CSV file to a pandas DataFrame in the Python programming language. Don’t hesitate to tell me about it in the comments section, in case you have additional questions and/or comments.

 

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