Function call and execution flow in Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What happens when a function is called in Python?

The program pauses at the call, jumps to the function's code, runs it, then returns to continue after the call.

intermediate

What is the 'call stack' in function execution?

It is a structure that keeps track of active functions. Each call adds a frame; returning removes it.

beginner

Why does a function return a value?

To send back a result to where it was called, so the program can use that result next.

beginner

What happens if a function does not have a return statement?

It returns None by default, meaning no specific value is sent back.

intermediate

How does Python handle nested function calls?

Python completes the innermost function first, then uses its result in the outer function call.

What does the program do immediately after a function call?

A Jumps to the function's code and starts executing it

B Skips the function and continues the next line

C Ends the program

D Waits for user input

When a function is called, the program jumps to that function's code to run it.

What is stored in the call stack during function execution?

A Only the return values

B All variables in the program

C Active function calls and their local data

D User inputs

The call stack keeps track of active functions and their local information.

If a function has no return statement, what does it return?

A The last variable

B 0

C An error

D None

Functions without a return statement return None by default.

In nested function calls, which function runs first?

A None run

B The innermost function

C Both run simultaneously

D The outermost function

Python runs the innermost function first to get its result.

What happens after a function finishes executing?

A The program returns to the point after the function call

B The program restarts

C The program stops

D The function runs again automatically

After finishing, the program continues from where the function was called.

Explain the flow of execution when a function is called in Python.

Think about what happens step-by-step from call to return.

Describe what the call stack is and why it is important during function calls.

Imagine a stack of plates where each plate is a function call.