Python Functions for Generating Random Captcha and Password Strings

The following examples show how to use Python's random and string modules to create random alphanumeric strings that can serve as captchas, passwords, or bulk test data.

Single captcha-like code (method 1):

import random, string

def one_test():
    s = ""
    for i in range(0, 17):
        if random.randint(0, 1) == 0:
            # generate a letter
            s = s + chr(random.randint(65, 90))
        else:
            # generate a digit
            s = s + str(random.randint(0, 9))
    return s

Single password list (method 2):

import random, string

passwd = []
for i in range(20):
    if random.randint(0, 1):
        letter = random.choice(string.ascii_uppercase)
        passwd.append(letter)
    else:
        letter = random.choice(string.digits)
        passwd.append(letter)

print("".join(passwd))

Batch generation of multiple codes (method 3):

import random, string

def one_test():
    s = ""
    for i in range(0, 17):
        if random.randint(0, 1) == 0:
            # generate a letter
            s = s + chr(random.randint(65, 90))
        else:
            # generate a digit
            s = s + str(random.randint(0, 9))
    return s

def more_test(xxx):  # generate a custom number of codes
    aaa = []
    for i in range(0, xxx):
        aaa.append(one_test())
    print(aaa)

if __name__ == '__main__':
    more_test(10)

These snippets illustrate basic techniques for random string generation, useful for testing, security exercises, or creating simple verification codes.