Steven D'Aprano wrote: > On Thursday 18 August 2016 06:25, Terry Reedy wrote:
> Sure. But since the behaviour of def functions and lambda functions are > identical, writing a named def won't solve that problem. > > >> for section_name, line_number in text.parser.toc: >> def goto(line=line_number): >> text.yview(line) >> drop.add_command(label=section_name, command=goto) >> >> To me, this is much better and I intend to commit it. Thank you for >> prodding me to think through how bad the lambda form can be and to >> rewrite the loop so I don't cringe reading it. > > The use of a named function here adds next to nothing. Instead of some > number of anonymous functions called "<lambda>", you have an equal number > of functions all named "goto". There may be other lambdas that do something completely different. For someone not familiar with the code in question a name gives a good hint were to look. > There's no easy way to distinguish them, > and likely no real need to distinguish them -- they are simple enough that > you can be almost certain that they are correct just from reading the > code. So I don't see any benefit over this: > > for section_name, line_number in text.parser.toc: > drop.add_command(label=section_name, command=lambda > line=line_number: text.yview(line)) > > except that it is easier to fit in 79 columns :-) There is also >>> functools.partial(text.yview, line_number) functools.partial(<bound method Text.yview of <tkinter.Text object at 0x7f1539dfd1d0>>, 42) The repr() is unwieldy, but the underlying function and its arguments are there. -- https://mail.python.org/mailman/listinfo/python-list
