Python Coding challenge - Day 1191| What is the output of the following Python Code?

 

Code Explanation:

🔹 1. Defining a Generator Function

def gen():

✅ Explanation:

A function named gen is created.

Since it contains the yield keyword, it becomes a generator function.

A generator does not execute immediately when it is defined.

Current state:

Generator function created.

🔹 2. Starting the for Loop

for i in range(3):

✅ Explanation:

range(3) generates numbers from 0 to 2.

Values of i will be:

0

1

2

Visual:

Iteration 1 → i = 0

Iteration 2 → i = 1

Iteration 3 → i = 2

🔹 3. Using yield

yield i * 2

✅ Explanation:

yield returns a value and pauses the function.

Unlike return, the function does not end.

It remembers its current state and continues from the same place when next() is called again.

Formula:

Yield Value = i × 2

🔹 4. Creating the Generator Object

g = gen()

✅ Explanation:

Calling gen() does not execute the function.

Instead, it creates a generator object.

Current state:

g

↓

<generator object>

The loop has not started yet.

🔹 5. First next() Call

print(next(g))

✅ Explanation:

next(g) starts executing the generator.

Current value:

i = 0

Calculation:

0 * 2

Result:

0

yield returns:

0

The generator pauses here.

Output:

0

🔹 6. Generator Pauses

After returning 0, the generator does not restart.

It pauses at:

yield i * 2

Current position:

Waiting for next() call

🔹 7. Second next() Call

print(next(g))

✅ Explanation:

The generator resumes from where it stopped.

Loop continues with:

i = 1

Calculation:

1 * 2

Result:

2

yield returns:

2

Generator pauses again.

Output:

2

🔹 8. Current Generator State

The generator has processed:

i = 0 ✅

i = 1 ✅

Still remaining:

i = 2

If we call:

print(next(g))

Output:

4

because:

2 * 2 = 4

🎯 Final Output

0

2

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