import numpy as np
import numpy.random
import string
import time
import os

l = list(string.ascii_letters)

s = time.time()
t_gen = 0
t_wrt = 0
chars = 0

with open("rnd_str.txt", 'w+') as f:
    f.write("")

for i in range(30):
    t = time.time()
    data = np.random.choice(l, 2*1024*1024)
    t_gen += time.time() - t

    t = time.time()
    with open("rnd_str.txt", 'a') as f:
        data.tofile(f)
    t_wrt += time.time() - t
    chars += data.shape[0]

size = os.path.getsize("rnd_str.txt")

print("\nTotal time: %.3f\nChars: %d\nFile size: %d\nGeneration time: %.3f\nWriting time: %.3f" % (
    time.time() - s, chars, size, t_gen, t_wrt))