How to Write List to CSV in Python

  1. Write List to CSV in Python Using the csv.writer() Method
  2. Write List to CSV in Python Using the Quotes Method
  3. Write List to CSV in Python Using the pandas Method
  4. Write List to CSV in Python Using the numpy Method

A CSV file can store the data in a tabular format. This data is a simple text; every row of data is called the record, and each one can be separated with commas.

This article will discuss the different methods to write a list to CSV in Python.

Write List to CSV in Python Using the csv.writer() Method

Let’s first import the csv module:

import csv

Suppose we take the following entries to write into a CSV file.

RollNo,Name,Subject
1,ABC,Economics
2,TUV,Arts
3,XYZ,Python

Now, the complete example code is as follows:

import csv

with open('students.csv', 'w', newline='') as student_file:
    writer = csv.writer(student_file)
    writer.writerow(["RollNo", "Name", "Subject"])
    writer.writerow([1, "ABC", "Economics"])
    writer.writerow([2, "TUV", "Arts"])
    writer.writerow([3, "XYZ", "Python"])

If you run the above codes, the students.csv file will be created, row-wise, in the current directory with the entries that are present in the code. The csv.writer() function will create the writer() object, and the writer.writerow() command will insert the entries row-wise into the CSV file.

Write List to CSV in Python Using the Quotes Method

In this method, we will see how we can write values in CSV file with quotes. The complete example code is as follows:

import csv
list = [["RN", "Name", "GRADES"],
    [1, 'ABC', 'A'],
    [2, 'TUV', 'B'],
    [3, 'XYZ', 'C']]
with open('studentgrades.csv', 'w', newline='') as file:
    writer = csv.writer(file, quoting=csv.QUOTE_ALL,delimiter=';')
    writer.writerows(list)

The studentgrades.csv file will be created in the current directory. The csv.QUOTE_ALL() function places double quotes on all the entries, using a delimiter ; for separation.

Output:

RN;"Name";"GRADES"
1;"ABC";"A"
2;"TUV";"B"
3;"XYZ";"C"

Write List to CSV in Python Using the pandas Method

This method uses the Pandas library, which holds a complete data frame. If you do not have this library installed on your PC, you can use an online tool called Google Colab.

The complete example code is as follows:

import pandas as pd
name = ["ABC", "TUV", "XYZ", "PQR"] 
degree = ["BBA", "MBA", "BSC", "MSC"] 
score = [98, 90, 88, 95] 	
dict = {'name': name, 'degree': degree, 'score': score} 
df = pd.DataFrame(dict) 
df.to_csv('test.csv')

Output:

	name	degree	score
0	ABC	    BBA	     98
1	TUV	    MBA	     90
2	XYZ	    BSC	     88
3	PQR	    MSC	     95

This method writes the Python list into a CSV file as a data frame.

Write List to CSV in Python Using the numpy Method

This method uses the numpy library to save a list to a CSV file in Python. The complete example code is as follows:

import numpy as np 
list_rows = [ ['ABC', 'COE', '2', '9.0'],['TUV', 'COE', '2', '9.1'], ['XYZ', 'IT', '2', '9.3'],['PQR', 'SE', '1', '9.5']]  
np.savetxt("numpy_test.csv", list_rows, delimiter =",",fmt ='% s')

The savetxt() function of the numpy library will write a CSV file from the Python list.

Output:

ABC	 COE	2	9
TUV	 COE	2	9.1
XYZ	 IT	2	9.3
PQR	 SE	1	9.5

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