Скорее всего уже слышали, что складывать строки через + это плохая практика. Падение производительности, и всё такое. Без лишних слов, давайте измерять:
from timeit import timeit
def t1():
# складываем 10 строк через + из переменной
t = 'text'
for _ in range(1000):
s = t + t + t + t + t + t + t + t + t
def t2():
# склеиваем список строк через метод join
arr = ['text'] * 10
for _ in range(1000):
s = ''.join(arr)
def t3():
# складываем через + но не из переменной а непосредственно инлайн объекты
for _ in range(1000):
s = 'text' + 'text' + 'text' + ... # всего 10 раз
Теперь каждую строку склейки запустим по 10М раз
>>> timeit(t1, number=10000)
0.21951690399964718
>>> timeit(t2, number=10000)
1.4978306379998685
>>> timeit(t3, number=10000)
0.2213820789993406
Хм, а нам говорили что через "+" это плохо и медленно ))) 😁
Тут стоит учитывать, что речь идёт о склейке множества длинных строк.
Давайте изменим условия:
def t4():
t = 'text'*100
for _ in range(1000):
s = t + t + t + t + t + t + t + t + t
def t5():
arr = ['text'*100] * 10
for _ in range(1000):
s = ''.join(arr)
def t6():
for _ in range(1000):
s = 'text'*100 + 'text'*100 + ... # всего 10 раз
>>> timeit(t4, number=10000)
12.795130728000004
>>> timeit(t5, number=10000)
2.642637542999182
>>> timeit(t6, number=10000)
0.2184546610005782
Вот, уже другой разговор, сразу видна разница, в среднем в 6 раз. Но погодите, почему последний тест t6() по скорости такой же как и t3()? Ведь строки теперь в 100 раз длиннее!
Это вопросы оптимизации кода, какие простые изменения ускоряют или замедляют выполнение программы. Мы столкнулись с примером обхода обращения к переменной. Например, именно так работает директива #define в С++, во время компиляции подставляя значение переменной вместо ссылки на неё.
В Python это тоже работает, но часто ли вы сможете встретить такой способ работы со строками? К сожалению, способ почти только теоретический.
В целом, тесты показали то, что мы хотели. Делаем выводы самостоятельно.
Полный листинг 🌍
#tricks
Respect the Spindle
by Abby Franquemont
Download
Enjoying a resurgence in popularity thanks to the current trend of DIY crafts, the hand spindle remains one of the most productive, versatile, and convenient tools for creating stunning fiber arts from home, as this beautifully illustrated guide from a veteran spinner and spindle aficionado demonstrates. With step-by-step instructions, this essential manual details the basic steps of spinning and then advances to the more complicated spinning wheel, showing how to use the spindle to make specific types of yarn, explaining traditional spindle spinning techniques, and detailing five simple projects designed to instill confidence in creating a variety of yarns with this simple tool. Combining fascinating historical narratives, traditions, and cultures from around the globe with vivid photography, this all-encompassing tour of the spindle also boasts easy-to-follow, contemporary techniques and styles that affirm the tool's enduring legacy.
#spinning
More thoughts on spinning.
I hope you'll indulge me with this detour/personal journey of mine.
Processing and spinning wool seems an unnecessary and tedious task when there is everything else to worry about. However, some animals, like sheep, can be dual purpose. Why not learn to utilize what else they have to offer?
For some of us, the fiber is so worthwhile that we'd keep animals just for that purpose alone! (Hence my alpaca obsession - plus they are cheap therapy!)
The reason why I'm starting to love spinning is because it is a mindful, yet mindless task that you can simply pick up and tend to without thought. Just feeling, stretching, twirling.
With knitting, you must actively think. Processing and spinning fiber is a perfect complement to the art, a duty to put thoughts to rest and focus only on how the fiber feels.
It's not about getting it done quickly, it's not about profit. It's about enjoying your time and feeling empowered in what you're able to create with your own hands.
#spinning#alpaca
Elaborating on the Removal of Vegetable Matter (specifically when there's a lot of it)
And thoughts on your environment's impact on how dirty your fleece gets
#spinning#alpaca
How things are going.
This is a Golding top whorl drop spindle. They kindly sent me some kind of hideous fiber to experiment with, which I gladly did, although I found it awful to work with. Probably not the best intro to spinning.
I skirted and clouded a small portion of Obsidian's fleece to see how it does in comparison. My hand carders are still sitting in my PO box, so I still have to wait for that - it makes the fluffing easier. No wash, just taking bits of vegetable matter out, and I gotta tell ya, it is really messy. Fluffing and picking seemed to get a lot of dust out, so spinning isn't that dirty, actually. It may even be giving it more grip.
It is far easier to spin that I expected. People say alpaca is not a good wool to start with because it's too slippery, but I found it extremely easy to draft and spin evenly. It may have something to do with the generous 3" of staple length.
I will try to record a short video of the skirting process tomorrow.
Still new, but learning.
#spinning#alpaca
Thus begins the processing of raw alpaca wool for the first time - just so you know what my time is occupied by.
Once I master this, I will be happy to share the process.
I am learning to spin as well, and hopefully will produce a skein in not too much time.
This comes from our alpaca Obsidian, a gentle fellow who's very intelligent and sensitive.
#spinning#alpaca