Python 2 vs. Python 3: A retrospective

Post by TylerE » Sun, Nov 10, 2013, 2:59 AM UTC

yen223 wrote: post #57

jzwinck wrote: post #48

Earlier quoted context omitted.

You know what's funny? All of those things could have been done in Python 2.8, apart from the int division change. And the division change does as much harm as good, because lots of people use Python and also use another language where int division works the "old fashioned way"; for them (me) this change is counter-productive because it adds a pointless distinction. It is a great change for programming novices, for s…

The division change is good. I have a hard time understanding why you'd want 3/2 = 1 as the default behaviour.

    x = int(input(">>> "))
    a = x / 2
    append_int_to_magical_db(a)

Post by justinmk » Sun, Nov 10, 2013, 3:04 AM UTC

jzwinck wrote: post #48

justinmk wrote: post #35

I'd really like to see the video for these slides. But here's what caught my interest: Set and dict comprehensions {x**2 for x in range(10)} {x: x**2 for x in range(10)} Why reduce() must die: ... the applicability of reduce() is pretty much limited to associative operators, and in all other cases it's better to write out the accumulation loop explicitly. int [divided by] int should return float nonlocal Explicit non…

You know what's funny? All of those things could have been done in Python 2.8, apart from the int division change. And the division change does as much harm as good, because lots of people use Python and also use another language where int division works the "old fashioned way"; for them (me) this change is counter-productive because it adds a pointless distinction. It is a great change for programming novices, for s…

Post by takluyver » Sun, Nov 10, 2013, 3:31 AM UTC

TylerE wrote: post #62

yen223 wrote: post #57

Earlier quoted context omitted.

The division change is good. I have a hard time understanding why you'd want 3/2 = 1 as the default behaviour.

Imagine the following (admittedly bad, minimalistic to make my point) code x = int(input(">>> ")) a = x / 2 append_int_to_magical_db(a) If the division does a "naturaL" thing, you suddenly have a float "polluting" your integer algorithm, but it's _not consistent_. If the user enters "4", you get an int back. If they enter 5, you get a float.

Post by [deleted] » Sun, Nov 10, 2013, 3:39 AM UTC

pmelendez wrote: post #40

sillysaurus2 wrote: post #33

Earlier quoted context omitted.

__ is basically a namespace for official language extensions. How would you suggest they do it? Prevent "next()" from being a valid method name?

That has been addressed in some many other ways by several languages that goes from the C++ way where you actually have namespaces to the C way where you don't worry about it and pick another name. From all of them I find this the most odd way to address it, specially when python was supposed to improve legibility by design (at least for me those underscores are very distracting)

Post by rhubarbquid » Sun, Nov 10, 2013, 4:16 AM UTC

andyl wrote: post #42

It seems like I've been reading about the difficulties of Python V2 -> V3 for awhile. Why is that? Is this Python upgrade unusually difficult/ambitious? Or is the Python community just very reluctant to jump on new things?