postgres Database populate - python script

import random
import string

def random_char(y):
       return ''.join(random.choice(string.ascii_letters) for x in range(y))

def random_number(y):
       return ''.join(str(random.randint(0, 9)) for x in range(y))

f = open("insert.sql",'w');
for i in range(200):
    command = "INSERT INTO accounts(username,password,email,contact,postcode,age,height) VALUES('{}','{}','{}@gmail.com',{},{},{},{});".format(random_char(7),random_char(10),random_char(6).lower(),random_number(random.randint(8, 12)),random_number(random.randint(4, 7)),random.randint(13, 65),random.randint(130, 200))
    f.writelines(command+"\n")