Generate a large size of CSV file was filled random values. This script generates around 250MB size of the file. You can adjust two parameters `row` and `col` to generate the file which has desirable size.

generate_L_size_csv.py

import csv
import random

# 1000000 and 52 == roughly 1GB (WARNING TAKES a while, 30s+)
rows = 1000000
columns = 52

def generate_random_row(col):
    a = []
    l = [i]
    for j in range(col):
        l.append(random.random())
    a.append(l)
    return a

if __name__ == '__main__':
    f = open('sample.csv', 'w')
    w = csv.writer(f, lineterminator='\n')
    for i in range(rows):
        w.writerows(generate_random_row(columns))
    f.close()

@AndrewFarley Thanks for your comments.
This code was the first Python code I ever wrote, and I fondly remember writing it back then because I needed a large CSV file for testing.
I completely agree with the improvements you pointed out and have fixed it.
Thank you :)