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
⚡️
🇷🇺
🇺🇦⚔️ Ukraine Fronts on the Morning of 17 March⚡️
🔴#Sumy Direction:
🔴In #Sudzha Sector, west of the city in #Ukraine, the RFAF is fighting for #Zhuravka and in the direction of #Belovody to the south of it. To the east, battles for #Basovka are ongoing.
🟡 In #Russia, to the east, there are fierce battles for #Gogolevka.
🟡#Oleshnya remains under AFU control. For #Melovoy to the east of it, the situation is unclear.
🟡 For #Guyevo, battles continue.
🟡#Gornalin the far south of #Kursk region, remains under AFU control for now.
🗺 Map 1
🔴#Svatovo Front:
🔴 In #Kupyansk Sector, on the right bank of the Oskol River, north of #Kupyansk, the RFAF continue to advance.
🗺 Map 2
🔴 In #Borovaya Sector, fights for #Boguslavka's northern settlement outskirts continue.
🔴In #Liman Sector, fighting is taking place in the direction of #Zagryzovo - #Boguslavka.
🟡#Novolyubovka has been occupied by Russian forces.
🗺 Map 2
🔴#ChasovYar Direction:
🔴In #Toretsk Sector, fighting in the city continues.
🔴#Pokrovsk Direction:
🔴 On the right Flank, the battles for #Lysovka, where the RFAF took again control of its southwestern part, and #Novoukrainka continue.
🟡 In #Shevchenko, the AFU have consolidated in the northern part of the village. Periodically they try to enter the southern part, where they are defeated.
🎞 Video
🟡 In #Peschanoye, the AFU is trying to gain a foothold again. Most of the village is under Russian control.
🟡 In #Zverevo, Russian assault groups are attacking in the southeastern parts (north of #Peschanoye) and in the northwestern part.
🟡 In #Kotlino, the AFU counterattacks for the northwestern settlement outskirts.
🗺 Map 3
🔴 On the left Flank, the RFAF took the initiative and try to restore the situation in #Udachnoye. The eastern part of the settlement and most of industrial zone came under Russian control.
🗺 Map 3
🔴#Zaporozhye Direction:
🔴In the #Orekhov Section, Russian troops continue to attack with infantry units in the area of the conquered #Pyatikhatki settlement. Battles for #Shcherbaki and #MalyeShcherbaki to the west of it are ongoing. The AFU is counterattacking, also at #Stepovoye.
🗺 Maps @olegtsarov
📋Sources: ⚡️2M;
🇺🇦Fiend; 😼Kotenok
🕰17 Mar 2025; 06:34 GMT+3; #sum
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🇺🇦On Ukraine Observer you will find your daily independent Ukraine War Battle Update
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🇷🇺
🇺🇦⚔️ Ukraine Fronts on the Morning of 5 April⚡️
🔴#Sumy Direction:
🔴In #Sudzha Sector, to the west on Ukrainian soil, the battles for #Veselovka and #Zuravka continue.
🟡#Basovka has reportedly been captured by Russian forces {3rd black⬆️}.
🟡 In #Kursk region, the AFU still controls #Oleshnya. South of #Guyevo, there is reportedly fighting along the road to 'St. Nicholas Monastery' which is part of AFU controlled #Gornal.
🔴In #KrasnayaYaruga Sector, the villages of #Popovka and #Demidovka remain contested. Fighting continues.
🗺 All on Map 1
🔴#Kharkov Direction:
🔴In #Liptsy and #Volchansk Sections, positional battles, no change.
🔴#Svatovo Front:
🔴 In #Kupyansk Sector, intense fighting in the area of Oskol bridgeheads north of the city:
#Kamenka has been entered by Russians troops.
🗺 Map 2
🟡 For #Figolevka, to the south, reportedly the battle has begun again. About 2 weeks ago the AFU recaptured the settlement.
🟡 In #Kondrashovka's northeastern part, fighting continues, as well to its northwest in nearby #MalayaShapkovka's southeastern part (unconfirmed).
🔴 In #Borovaya Sector, without changes.
🔴In #Liman Sector, battles are taking place west of #BalkaZhuravka. The RFAF took #Novolyubovka. To the west, fighting towards #Novoye and #Katerinovka continues.
🔴For #Seversk Sector, no news.
🔴#ChasovYar Direction:
🔴In #ChasovYar and #Toretsk Sectors, without major changes.
🔴#Pokrovsk Direction:
🔴 On the right Flank, the battle for #Tarasovka is ongoing. Otherwise no major changes.
🔴 South of the City, the situation is reportedly as follows:
🟡 Near #SukhoyYar (AFU controlled), there are positional battles.
🟡#Lysovka is mostly under Russian control, with exception of its northwestern part.
🟡 At #Zelenoye' northeastern outskirts, there are counter-fights.
🟡 At #Novoukrainka, Russian forces press towards the settlement.
🟡#Shevchenko is RFAF controlled.
🟡 Northeast of #Peschanoye and in #Zverevo, Russian assault units are attacking.
🟡 In #Kotlino's northwestern part, counterattacks take place. The AFU try unsuccessfully to enter the settlement's industrial zone (which should be east of the mostly AFU controlled village).
🔴 On the left Flank, reportedly fierce counterbattles in the area of #Udachnoye. RFAF assault units are restoring the situation in the village's northern part and have made significant progress in the residential area towards the central part.
🟡#Uspenovka, according to RF MoD claims, shall been taken.
🔴#Komar Direction:
🔴In #Bogatyr Sector, fighting at #Andreyevka and for #Konstantinopol continued. Near #Bogatyr, the RFAF reportedly extended their control zone.
🔴 In #Komar Sector, no major changes.
🔴#Zaporozhye Direction:
🔴In the #Orekhov Section, the RFAF advanced along the forest belts south of #Kamenskoye to a depth of up to 500 m. Otherwise no major changes.
💥 In the #DPR, the AFU struck #Gorlovka, killing a woman and wounding 5 more civilians.
💥 In #Kherson Direction, the AFU struck several villages, wounding civilians.
💥#OldRussia:
🔵 In #Bryansk Region, the AFU damaged a PS in the village of #Lemeshovka, violating the agreement. Also several villages and an agricultural enterprise have been attacked.
🟡 In#Samara region, UAVs hit the 'JSC Promsintez Plant' in #Chapayevsk, which produces explosives.
🟡 In the Republic of #Mordovia, UAVs have hit the 'JSC Optic Fiber Systems Plant' in #Saransk, crucial for the RF defence industry.
📸 Picture
💥#RestUkraine:
🔵 The RFAF struck targets in #Kiev, #Zhitomir, #Sumy, #Vinnitsa and #Cherkassy regions at night.
🟡 In #KrivoyRog, there was a massive UAV attack. Claims on an alleged missile strike are contradictory, the published footage does not allow the incident to be assessed.
🎬 Video
⚠️ The Term 'Reportedly' indicates that it is unconfirmed!
🗺 Maps @olegtsarov; @petrenko_iHS
📋 Sources: CC; Tsarov; 🇺🇦Fiend;⚡️2M;🐈Cat😼VK
🕰As of 5 Apr 2025; 06:36 GMT+3;📃4 Apr
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🇺🇦On Ukraine Observer you will find your daily independent Ukraine War Battle Update