I just found this grandiose function in our code

```
def t(s):
return s
```

Easier to change function return unchanged input value than to remove its use from all code.

I did something similar yesterday but with a lambda. I needed to add an optional post processing function as an argument to another function but I hate None defaults as they add that ugly "if x is None" boilerplate, so my default post processing function was an identity function "lambda x: x". That should be built-in IMO.

Identity function is actually more useful than it looks like

It's something that we can't understand fellas. Something big. Something out of this world.

Enough with the joke. WTF?

I correct: This function is called exactly once.

@turbopixel It may be useful as a default but it's still strange nonetheless.

@Khepu I think all languages with first class functions have a built in identity function

Usefull in very specific cases, where methods are overridden, or bound to intances in runtime.
Also usefull for monkey patching runtimes.