[Timothycquinn]

Love this. I’ve written a ton of Python in recent years but never used the ‘is’ operator. After reading this I’m glad I did not.

I can see usecases but clearly it should be used sparingly.

[wzdd]

To be honest this response underscores the problem with pages like this. In Python, strings and numbers are objects, and “is” tells you if they are the same object. You wouldn’t compare strings or numbers in C using a pointer comparison, and you shouldn’t do it in Python either. The fact that it works sometimes in cpython is a coincidence.

It’s interesting to learn about how the interpreter is implemented, but that’s about it.

[kstrauser]

You should absolutely be using `is` where appropriate. `x is None` is almost always preferable to `x == None`. If you're checking for object identity, use `is`. If equality, use `==`. They're different use cases.

[maweki]

Especially since == can be overwritten, while 'is' can not.

[JoBrad]

How is that your response, after reading this article? The is operator checks whether the two items are the same object, which is critical in some circumstances.

[wodenokoto]

How do you check for None?

[stevesimmons]

Or check that two dicts really are the same object, as opposed to two different dict objects that just happen to have the same keys/values?

[Timothycquinn]

You are correct. I kind of took `is None` for granted as it just feels boilerplate when coding in Python.

Although I have written over a hundred thousand of lines of code in Python over the years; I use Python mostly for dev ops tooling, reporting, monitoring and automation so they don't get super complex and they mostly can lean on procedural programming patterns.

I could imagine complex frameworks needing heavy use of Objects that could lean on the 'is' keyword.

[thrdbndndn]

I personally do use "if var is None:", but can't you just use "if var == None"?