FYI, I found a package [*] which binds a value by function keyword (I'm not the author). Note that the package writes a value in the global (or raise an error if the name already exists in local) unlike your idea.
Thank you! Writing to a globals is an even more stripped-down version from the inteded behaviour, for example it would not work in comprehensions at all and would not work if function has the same local name. In fact comprehension/generator cases are the least interesting for me. I just wanted to minimize side-effects.