Python Coding challenge - Day 609| What is the output of the following Python Code?

 

Code Explanation:

1. Importing takewhile from itertools

from itertools import takewhile

This imports the takewhile() function from the built-in itertools module.

takewhile(predicate, iterable) returns elements from the iterable as long as the predicate (a function returning True/False) is true.

Once the predicate returns False for the first time, it stops and discards the rest of the elements, even if later elements would satisfy the predicate.

2. Defining a Generator Function

def numbers():

    for i in range(1, 10):

        yield i

This defines a generator function numbers().

The for loop iterates through numbers 1 to 9 (range(1, 10)).

yield i makes this a generator, so each number is produced one at a time when requested.

3. Using takewhile with a Lambda Predicate

print(list(takewhile(lambda x: x % 2 != 0, numbers())))

takewhile(lambda x: x % 2 != 0, numbers()):

Applies the lambda function to each number from the generator.

The lambda checks if a number is odd (x % 2 != 0).

Starts from 1 and continues only while the numbers are odd.

The moment it sees an even number, it stops completely (does not continue to later values).

list(...) converts the result from the iterator into a list.

print(...) prints the resulting list.

How It Executes Step-by-Step:

numbers() starts yielding values: 1, 2, 3, 4, ..., 9

takewhile checks:

1 → odd → included

2 → even → stops here

So only 1 is included in the result.

Final Output:

[1]

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