on writing a while loop for rolling two dice

[Peter Otten]

On 29/08/2021 12:13, dn via Python-list wrote:
> On 29/08/2021 20.06, Peter Otten wrote:
> ...
>> OK, maybe a bit complicated... but does it pay off if you want to
>> generalize?
>>
>>>>> def roll_die(faces):
>>      while True: yield random.randrange(1, 1 + faces)
>>
>>>>> def hmt(faces, dies):
>>      for c, d in enumerate(zip(*[roll_die(faces)]*dies), 1):
>>          if len(set(d)) == 1: return c, d
> 
> 
> Curiosity:
> why not add dies as a parameter of roll_die()?

Dunno. Maybe because I've "always" [1] wanted a version of 
random.randrange() that generates values indefinitely. It would need to 
check its arguments only once, thus leading to some extra

> Efficiency:
> - wonder how max( d ) == min( d ) compares for speed with the set() type
> constructor?

I did the simplest thing, speed was not a consideration. If it is, and 
dies (sorry for that) is large I'd try

first = d[0]
all(x == first for x in d)  # don't mind one duplicate test

For smaller numbers of dice I'd unpack (first, *rest) inside the for 
loop. But it's a trade-off, you' have to measure if/when it's better to 
go through the whole tuple in C.


> - alternately len( d ) < 2?
> - or len( d ) - 1 coerced to a boolean by the if?
> - how much more efficient is any of this (clever thinking!) than the
> OP's basic, simpler, and thus more readable, form?

It really isn't efficiency, it's a (misled?) sense of aesthetics where 
I've come to prefer

- for-loops over while, even when I end up with both to get the desired for

- enumerate() over an explicit counter even though there is the extra 
unpack, and you still need to initialize the counter in the general case:

for i, item in enumerate([]): pass
print(f"There are {i+1} items in the list.")  # Oops

> English language 'treachery':
> - one die
> - multiple dice

You might have inferred that I knew (or had looked up) the singular of 
dice, so this is but a momentary lapse of reason. It hurts me more than 
you, trust me. Not as much, as going on record with confusing they're 
and their, but still ;)

> (probably not followed in US-English (can't recall), particularly on
> computers running the Hollywood Operating System).

I've come to the conclusion that International English is hopelessly and 
inevitably broken. That's the price native speakers have to pay for 
having they're (oops, I did it again!) language used as lingua franca.

> Continuous Education:
> Thanks for the reminder that enumerate() can be seeded with a "start" value!

[1] I think I've suggested reimplementing the whole module in terms of 
generators -- can't find the post though.