What's the difference between is and == in Python?

[Istituto-freudinttheprodev]

Hi everyone! I'm trying to understand the difference between is and == in Python.

I saw this code:

a = [1, 2, 3]
b = [1, 2, 3]
print(a == b)  # True
print(a is b)  # False
Why does == return True but is returns False?
Can someone explain this in simple terms? 🙏

[debonte]

See https://docs.python.org/3.11/reference/expressions.html#is-not. is tests is two objects are the same object, whereas == tests if they have the same value.

[MatteoMgr2008]

Great question! This is a very common confusion in Python.

---

== checks if the values are equal
is checks if both variables point to the exact same object in memory

---

In your example:

a = [1, 2, 3]
b = [1, 2, 3]
a == b → True because the contents of both lists are equal

a is b → False because they are two different objects in memory

You can prove it by checking their IDs:

print(id(a))
print(id(b))

They'll be different!

Now check this:

x = [1, 2]
y = x
print(x is y)  # True → both point to the same object

[Istituto-freudinttheprodev]

thank you so much!