Variables in python right use

Question

Given variables a, b:

b = 3

a = b++

a = --b

How do you write this correctly in Python?

In python a statement doesn't return anything. also `b++` is invalid in python. — Ashwini Chaudhary, Dec 23 '12 at 20:09
Duplicate of https://stackoverflow.com/questions/3654830/why-are-there-no-and-operators-in-python — General Grievance, May 17 '23 at 22:32

score 10 · Answer 1 · answered Dec 23 '12 at 20:10

10

From The Zen of Python:

Explicit is better than implicit

So, let's write:

b = 3
a = b; b +=1
b -= 1; a = b

answered Dec 23 '12 at 20:10

Don

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St. Hand · Answer 2 · 2012-12-23T23:05:17.780

There are no increment/decrement (++/--) operators in Python. This is because integers in Python are immutable (can't be modified, only reassigned). So let's break this down and emulate their behavior.

What does b++ do? It evaluates to b, then increments b. Therefore, we write this as:

a = b
b += 1

Now onto --b. It decrements b, then evaluates to the new value of b. In Python:

b -= 1
a = b

Put it all together and we get:

b = 3
a = b
b += 1
b -= 1
a = b

score 2 · Answer 3 · answered Dec 23 '12 at 20:07

2

In Python, you cannot do b++. There is no plus plus.

There is the operator +=, so you could this kind of stuff:

b = 3

b += 1

b -= 1

Or simply:

b = 3

a = b + 1

a = b - 1

answered Dec 23 '12 at 20:07

jackcogdill

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Variables in python right use

3 Answers3