[Python-ideas] Runtime assertion with no overhead when not active

[Serhiy Storchaka]

05.05.18 11:04, Eloi Gaudry пише:
>     Briefly, the idea is to add a new assert that can be switch on/off
>     depending on some variable/mechanism at runtime. The whole point of
>     this assert is that it should not bring any overhead when off, i.e.
>     by avoiding evaluating the expression enclosed in the runtime
>     assert. It thus relies on Python grammar.

You should have an overhead for checking if it is switched on/off, 
isn't? And this overhead is virtually the same as testing the value of 
the global boolean variable.

> runtime_assert( expr )
> 
> #would result in if expr and runtime_assert_active:
> 
> print RuntimeAssertionError()

How this will be different from

     if debug and not expr:
         print(RuntimeAssertionError())

?