Generate 10 random 3-letter strings

Question

This is a toy project and I am a beginner in Python.

I need to create 10 random 3-letter strings, where characters are a - z.

This is my implementation:

import random

def random_char():
    return random.randint(97, 122)

three_letter_words = []
for i in range(0, 10):
    three_letter_words.append(chr(random_char()) + chr(random_char()) + chr(random_char()))

I really do not like the part where I call chr(random_char()) 3 times.

How can I improve this to make it more compact and cleaner?

Answer 1

Python 3.6 introduced random.choices, which allows you to write this even more succinctly than using random.choice:

from random import choices
from string import ascii_lowercase

three_letter_words = ["".join(choices(ascii_lowercase, k=3)) for _ in range(10)]

Answer 2

1. a much more readable way of specifying that character range:

   random.choice(string.ascii_lowercase)
   

2. To get a string of n characters:

   ''.join([random.choice(string.ascii_lowercase) for _ in range(n)])
   

Answer 3

In addition to @l0b0's answer:

To generate cryptographically secure random strings (since this is a toy project, why not use a CSPRNG? it's a useful thing to learn):

import string

# only needs to be initialized once
import random
csprng = random.SystemRandom()

# alternatively, the "secrets" module is meant for generating strong csprng numbers
import secrets
csprng = secrets.SystemRandom()

# uses @Graipher's suggestion of .choices()
def random_string(len = 3, charsets = string.ascii_lowercase):
    return ''.join(csprng.choices(charsets, k = len))

three_letter_strings = [random_string() for _ in range(10)]

print(three_letter_strings)

"""
example output:
['ebi', 'hbg', 'hlm', 'rhp', 'eka', 'uja', 'uhi', 'lju', 'vvf', 'qtj']
"""


"""
alternatively, below is likely faster
if you want to do this a lot more than 10 times

see: https://stackoverflow.com/a/2970789
"""

import itertools

three_letter_strings = [random_string() for _ in itertools.repeat(None, 10)]

print(three_letter_strings)

Tested with Python 3.6.5