[Flask] Shouldn't is and == operator work same way while doing string comparisons?

[Cameron Simpson]

On 04May2019 00:41, Arup Rakshit <ar at zeit.io> wrote:
>I tested the both while in REPL.

Testing only tells you what happens in your test, with a aprticular 
environment. It doesn't inform you about the language specification, 
except in so far as a failed test might tell you that your assumption 
was incorrect.

>They work same, why it is then different then flask app code?

Python interning small strings is an implementation detail, not part of 
the language specification. So there is no explicit guarantee that 2 
strings with the same value are the same string object, even for small 
strings.

If you want to act on the value of something, use ==. Using "is" is NOT 
FOR THAT. It is to check if 2 object references refer to the same 
object. This is rarely what you want; it is most useful with singletons 
such as sentinels.

Cheers,
Cameron Simpson <cs at cskk.id.au>