Iter and next methods

Hello all
See the following sample for these two methods:

mytuple = ("apple", "banana", "cherry")
myit = iter(mytuple)
print(next(myit))
print(next(myit))
print(next(myit))

The output will be:
apple
banana
cherry

Now I change the code to:

mytuple = ("apple", "banana", "cherry")
# myit = iter(mytuple)
print(next(iter(mytuple)))
print(next(iter(mytuple)))
print(next(iter(mytuple)))

The new output will be:
apple
apple
apple

What is the problem? Why does it not work as the first output?

Because you’re making a new iter each time, and it starts from the beginning of the list.

Specifically, this is in the docs:

A container object (such as a list) produces a fresh new iterator each time you pass it to the iter()

1 Like

Thank you very much James.
Would you tell me how can I change the code to make it correct? Actually I want to use both next & iter methods together in one line not separately. Is it possible?

The first code you have is already correct. [1] You need to create an iterator with iter once, first, and save it, then call next repeatedly on that same saved iterator.


  1. Assuming your goal here is to iterate over some collection “manually”, you haven’t actually stated explicitly what you want to accomplish. ↩︎

1 Like

Why do you want to use them both on the same line?
What problem does that solve?

Are you asking how to make you second version of code work?
That is not possible. You need the myit variable.

Because the suggested code provided by ChatGPT was using both together. So I want to know if there is a way to use it as ChatGPT suggested or not?

ChatGPT is wrong.

Edit:

Just to be completely clear:

next(iter(obj))

is perfectly valid Python code but it will always and only do exactly the same thing: return the first item of obj (or raise StopIteration if there are no items). Which is why doing it more than once is probably not useful to do.

2 Likes

ChatGPT doesn’t know anything about anything, it just makes up stuff that looks plausible. Don’t rely on it to do anything correctly.

2 Likes

Thank you. I got it.

Thank you too. I got it.

You say that as if you imagine that ChatGPT somehow knows what
it’s talking about. It doesn’t. It spouts random nonsense that
sometimes happens to resemble meaningful English or program code
or whatever you asked it about. You can’t rely on it to write
code for you, or anything else.

Dear James;
I modified the code as you said, but the output is the same as before. I mean it does not go to the next question and iterates first question. Do you have any idea helps me?
The total code is:

import telebot

bot = telebot.TeleBot('*************************************************************')  # Replace with your bot token

# Questions and answers stored in a dictionary
questions = {
    "What is the answer to question 1": "A",
    "What is the answer to question 2": "B",
    "What is the answer to question 3": "C"
}

# Initialize the current_question outside of the functions
current_question = None

# Start command handler
@bot.message_handler(commands=['start'])
def start_message(message):
    global current_question
    bot.reply_to(message, "Welcome to the Quiz Bot! Please answer the following questions:")
    # Start the question answering loop
    current_question=iter(questions)
    current_question = next(current_question, None)
    bot.send_message(message.chat.id, current_question)
# Answer handler
@bot.message_handler(func=lambda message: True)
def answer_question(message):
    global current_question
    # global questions  # Access the global questions dictionary
    # Check if the user's answer is correct for the current question
    correct_answer = questions[current_question]
    if message.text.lower() == correct_answer.lower():
        bot.reply_to(message, "Correct!")
        # Move on to the next question
        current_question=iter(questions)
        current_question = next(current_question, None)
        if current_question:
            bot.send_message(message.chat.id, current_question)
        else:
            bot.send_message(message.chat.id, "Congratulations! You have answered all the questions correctly.")
    else:
        bot.reply_to(message, "Incorrect. The answer is " + correct_answer + ".")

bot.polling()

Dear Bryan;
Do you have idea about:

You need a loop that works it way over the iterator.
I do not see a loop in the code you provided.

This always uses the first question. The iterator must be setup outside the function. Do not use the same variable name for the iterator and a value returned by next.

I could not modify it. Could you do it?