このコードはどのようにして一意の文字を26回生成しますか？

私はいくつかのコメントでコードを説明しようとします

ただし、最初に、プログラムの縮小版を紹介します。

import random
import string

alpha = list(string.ascii_uppercase) # generate a list from the alphabet iterator
print(alpha) # print the alphabet
random.shuffle(alpha) # shuffle the alphabet
print(''.join(alpha)) # print the shuffled alphabet

そしてここにあなたのプログラムの説明があります

# This program outputs the chars from A-Z in a random order

import random # import random used to generate random numbers

alpha = [" "] * 26 # multiply the ' ' string 26 times results in a array with 26 spaces [' ', ' ', .....]
# This array will later be set to the alphabet

def unique_char():
    # This function picks char in a fancy way from alpha
    # Tut it will never return a char i has previosly return
    # So all piked chars are only picked ones

    notfound = True # set a boolen to true (this is called flag)
    while (notfound): # while the flag notfount is true repeat that step
        possible_pos = random.randint(0,25) # generate a random number between 0 and 25
        # alpha[possible_pos] will return the a char in the alpha array on the random position from the previos line
        
        if alpha[possible_pos] != "*": # set notfound to false(exit the loop) if the array alpha hasn't a '*' in alpha[possible_pos]
            notfound = False

        new_char = alpha[possible_pos] # set new char to alpha[possible_pos](explaint previosly)
        alpha[possible_pos] = "*" # and set alpha[possible_pos](explaint previosly) to '*'
         # ↑ That means if the random number is again the same number we will exit the loop
    return new_char # return the latest char from alpha

def main():
    for i in range(26):
        alpha[i] = chr(i+65) #genderates a-z
        # chr converts a asci number to a char
    # fill alpha with 'A-Z'

    print(alpha) # print the lphabet

    for count in range(26): # generate 26 unique chars that means every char is generated one time (time inefficiently)
        good_char = unique_char() # generate the random char
        print(good_char, end="") # print the random char without newline -> end=""
    print() # print an empty string

main() # call the main function