Swap Variables — PyBasic

Swapping Two Variables

Imagine you have two boxes: one labeled

containing

, and one labeled

containing

. How do you swap them so

has

and

has

In most programming languages, you'd need a third temporary box. But Python has an elegant one-line trick:

a = 10
b = 20

a, b = b, a    # Swap!

print(a)   # → 20
print(b)   # → 10

How Does This Work?

The line

a, b = b, a

does two things simultaneously:

◆
Right side first: Python reads
```
b, a
```
and creates a temporary pair
```
(20, 10)
```
◆
Then assigns: It puts
```
20
```
into
```
a
```
and
```
10
```
into
```
b
```

This is called tuple unpacking — Python packages the values, then unpacks them into the variables. You don't need to understand tuples yet; just know this trick works!

💡

💡 This is Pythonic: Python has many elegant shortcuts like this. Writing code "the Python way" is called being Pythonic.