On Mon, 21 Feb 2022 at 16:48, Avi Gross via Python-list <python-list@python.org> wrote: > > Amusingly, Greg, if you had a system where the un-named anonymous function > was to be named the unique value of the empty string, then a second such > anonymous function definition would over-write it, as with any named > function. The kind of anonymous function we are more used to might be > something you can create as say elements of a list so you have a list of > functions you can access as in f[0] but in a sense that has a name as it can > be accessed as a component of the data structure called f. I am not sure if > python would trivially let you create that. But the point is if you want to > be able to make many such pseudo-anonymous functions, in the end, there can > only be one. >
Functions in Python have two different concepts of "name", which aren't always the same. One is the way that you refer to it; the other is its __name__ attribute (and related attributes like __qualname__). An anonymous function doesn't necessarily have to lack a name, per se; it simply doesn't have a very interesting name: >>> (lambda: 1).__name__ '<lambda>' >>> (lambda: 2).__name__ '<lambda>' >>> (lambda: 3).__name__ '<lambda>' If you want to refer to them as f[0] etc, they can have arbitrary names, which may or may not themselves be meaningful. I frequently build a dictionary or list of functions by decorating standard 'def' statements: funcs = [] @funcs.append def spam(): ... @funcs.append def ham(): ... They still have __name__ attributes, but it's absolutely fine to double them up, since they're going to be looked up via the list. (Though there's still value in having at least *some* name on them, since it shows up in backtraces.) There's very little reason to have a function that actually doesn't have a name. It's usually fine to give it an arbitrary and meaningless name. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
