how to save file in csv format in python code example

Example 1: code how pandas save csv file

df.to_csv('out.csv')

Example 2: python convert dat file to csv

import csv

with open("infile.dat") as infile, open("outfile.csv", "w") as outfile:
    csv_writer = csv.writer(outfile)
    prev = ''
    csv_writer.writerow(['ID', 'PARENT_ID'])
    for line in infile.read().splitlines():
        csv_writer.writerow([line, prev])
        prev = line

Example 3: python save as csv

import numpy as np
np.savetxt('data.csv', (col1_array, col2_array, col3_array), delimiter=',')