Given variables a, b:
b = 3
a = b++
a = --b
How do you write this correctly in Python?
3 Answers
From The Zen of Python:
Explicit is better than implicit
So, let's write:
b = 3
a = b; b +=1
b -= 1; a = b
Comments
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
Comments
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
b++is invalid in python.