Python Coding challenge - Day 1258| What is the output of the following Python Code?

 

Code Explanation:

1. Import partial

from functools import partial

functools is a built-in Python module.

partial is a function available inside functools.

It is used to fix some arguments of an existing function and create a new function.

2. Define the calc() Function

def calc(a, b, c):

Here, we create a function named calc.

It accepts three parameters:

a

b

c

For example:

calc(2, 4, 5)

means:

a = 2

b = 4

c = 5

3. Perform the Calculation

return a * b + c

The function calculates:

a × b + c

For example:

2 × 4 + 5

= 8 + 5

= 13

4. Create a Partial Function

f = partial(calc, 2, c=5)

⭐ This is the most important line.

partial() creates a new function from calc() while fixing some arguments.

Here:

a = 2

c = 5

are fixed.

Only b needs to be supplied later.

So we can think of f as:

f(b) → calc(2, b, 5)

5. First Function Call

x = f(4)

The 4 becomes the remaining parameter b.

Therefore:

a = 2

b = 4

c = 5

Now calculate:

2 × 4 + 5

= 8 + 5

= 13

Therefore:

x = 13

6. Second Function Call

y = f(10)

Again, a and c are already fixed.

a = 2

b = 10

c = 5

Calculation:

2 × 10 + 5

= 20 + 5

= 25

Therefore:

y = 25

7. Print the Values

print(x, y)

At this point:

x = 13

y = 25

So the output is:

13 25

🔄 Internal Working

This:

f = partial(calc, 2, c=5)

can conceptually be understood as:

Original:

calc(a, b, c)

Fixed:

a = 2

c = 5

Remaining:

b

Therefore:

f(4)

   ↓

calc(2, 4, 5)

   ↓

13

and:

f(10)

   ↓

calc(2, 10, 5)

   ↓

25

📊 Execution Table

Expression a b c Result

f(4) 2 4 5 13

f(10) 2 10 5 25

🧠 Key Concept

partial() pre-fills arguments of a function.

Instead of repeatedly writing:

calc(2, 4, 5)

calc(2, 10, 5)

we fix the common arguments once:

f = partial(calc, 2, c=5)

and then provide only the changing argument:

f(4)

f(10)

🎯 Final Output

13 25

400 Days Python Coding Challenges with Explanation