Python’s iter() Function

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Python’s iter() function is a powerful tool for working with iterable objects and iterators. In this comprehensive guide, we’ll explore the intricacies of iter(), covering its syntax, applications, and practical examples to help you harness its full potential in Python programming.

Understanding iter() Function:

The iter() function in Python is used to create an iterator from an iterable object. Its syntax is as follows:

iter(object[, sentinel])
  • object: The object to be converted into an iterator.
  • sentinel (optional): A value that, if provided, is used to stop iteration.

Example 1: Basic Usage

Let’s start with a simple example:

my_list = [1, 2, 3, 4, 5]
my_iter = iter(my_list)
print(next(my_iter))  # Output: 1
print(next(my_iter))  # Output: 2

Here, we create an iterator from a list using iter(). We then use the next() function to iterate through the elements of the list.

Example 2: Using iter() with Custom Objects

You can also use iter() with custom objects by implementing the __iter__() method:

class MyIterator:
    def __init__(self, max_limit):
        self.max_limit = max_limit
        self.current = 0
    def __iter__(self):
        return self
    def __next__(self):
        if self.current < self.max_limit:
            self.current += 1
            return self.current
            raise StopIteration

my_iter = iter(MyIterator(5))

for num in my_iter:

In this example, we define a custom iterator class MyIterator, which generates numbers up to a maximum limit. We then use iter() to create an iterator from an instance of this class and iterate through it using a for loop.

Example 3: Using iter() with a Callable Sentinel

You can also use a callable as a sentinel value to stop iteration:

import random
def random_generator():
    while True:
        num = random.randint(1, 100)
        yield num
        if num == 50:
random_iter = iter(random_generator(), 50)
for num in random_iter:

Here, we create a generator function random_generator() that yields random numbers. We then use iter() with a callable sentinel (random_generator()) and stop iteration when the generated number equals 50.

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