On Mon, Apr 30, 2018 at 08:09:35AM +0100, Paddy McCarthy wrote: [...]
A PEP that can detract from readability; *readability*, a central tenet of Python, should be rejected, (on principle!), when such objections are treated so dismissively.
Unless you have an objective measurement of readability, that objection is mere subjective personal preference, and not one that everyone agrees with. I for one think that used wisely, binding expressions will be *more* readable than the alternatives. (Even though := is not my preferred syntax.) The "not readable" objection has been made, extremely vehemently, against nearly all major syntax changes to Python: - comprehensions? not readable, easy to abuse, hard for beginners to comprehend; - decorators? not readable, looks like Perl with the arbitrary use of @ symbol, hard to understand; - ternary if operator? not readable, doesn't look enough like C, weird order; - augmented assignments += etc -- not readable, too terse, requires the reader to be familiar with C. I was guilty of making that last one. And if I had been around for the debate over decorators, I probably would have hated them too. But all four additions to the syntax have been *great* for the language, despite the nay-sayers. I still know people with many years experience in Python who say they don't get comprehensions, and of course it is true that they are hard for beginners to get. But the advantages from comprehensions is immeasurably greater than the disadvantages. Will this PEP be like comprehensions or decorators, and completely change the way we write Python code (for the better)? I doubt it. But I expect it will be like augmented assignment and the ternary if: it will make certain kinds of code more pleasurable to write *and read*, and when it doesn't, people won't use it. -- Steve