He mau hiʻohiʻona ʻokoʻa ka For loop ma Python ma mua o nā ʻōlelo papahana ʻē aʻe. Ke waiho nei au iā ʻoe i kaʻu e aʻo nei e loaʻa i ka mea maikaʻi loa mai kekahi o nā puka lou i hoʻohana nui ʻia.
Ma Python ua manaʻo ʻia e hoʻololi i kahi mea iterable, inā he papa inoa, mea, a i ʻole kekahi mea.
ʻO ka hale ma lalo nei
h2=[ 'Valencia', 'Castellón', 'Alicante'] for j in h2: instructions
Eia ka h2 he mea iterable no ka laʻana he papa inoa h2=[ 'Valencia', 'Castellón', 'Alicante']. E loaʻa i ka loop 3 mau hoʻololi, ma ka mua j=Valencia ma ka lua ka hoʻololi j=Castellón.
A me kēia hiki iā mākou ke wehewehe i nā ʻōlelo aʻoaʻo a mākou e makemake ai, e hoʻomanaʻo mau ana i ka indentation, kahi mea koʻikoʻi ma Python a he nui ka poʻe i haʻalele, loaʻa nā hewa i ke code.
E hoʻololi no ka loop i ka helu pololei.
Inā makemake mākou e hana hou i kekahi mau manawa e like me ka hiki iā mākou ke hana ma C ++ pono mākou e hoʻohana i ka laulā (). No ka hana hou ʻana i 10 mau manawa e hoʻohana mākou i kahi
for element in Range(9): instructions
Hoʻokomo mākou i 9 a ʻaʻole 10 no ka mea hoʻomaka ka Range mai ka 0, no laila mai ka 0 a hiki i ka 9 he 10 iterations a i ʻole ka huli ʻana o ka loop.
ʻO ka ʻike ʻana i ka Range () hiki iā mākou, ma kahi o ka hoʻokomo ʻana i kahi helu i loko, e hoʻokomo i kahi loli, kahi e loaʻa ai iā mākou ka mana nui.
var = 10 for element in Range(var): instructions
He nui nā koho o ka hana Range, e kamaʻilio wau e pili ana iā ia ma kahi pou ʻē aʻe, i ʻole e hoʻohui i ka ʻike a hoʻomohala e like me ka hiki.
Hiki ke hana hou aku no ka hoomalu ana i ke kahe o ka loop loop.
Wehewehe a hoʻomau i nā ʻōlelo
Aia nā hiʻohiʻona maikaʻi loa 2 e hiki ai iā mākou ke hana i kahi loop no ka hana pono, fon ka hoʻomaha a me ka hoʻomau. Hoʻohana pinepine ʻia lākou me nā kūlana, inā, e nānā inā he ʻoiaʻiʻo kekahi.
Hana lākou i nā puka lou, a aia kekahi ʻōlelo hoihoi ʻē aʻe i hala, ʻo ia kahi ʻōlelo i hoʻokō ʻia akā ʻaʻohe mea a kūpono no ka wā e makemake ai mākou e wehewehe i kahi ʻano e koi ai i nā kauoha akā makemake mākou e kau iā lākou ma hope (ʻo nā ʻōlelo. ʻaʻole pono no kēia)
Makuakane
Me ka hoʻomaha hiki iā mākou ke haʻalele i ka loop i kēlā me kēia manawa. E like me kāu e noʻonoʻo pono ai. He ʻoiaʻiʻo aia kekahi mau hale e like me While,
numeros = [1, 2, 4, 3, 5, 8, 6] for n in numeros: if n == 3: break else: print('No se encontró el número 3')
E hoomau
Hoʻoholo ia iā mākou e hele i ka ʻāpana aʻe i ka loop.
numeros = [1, 2, 4, 3, 5, 8, 6] for n in numeros: if n == 3: continue else: print('No se encontró el número 3')
https://j2logo.com/bucle-for-en-python/
No… ʻē aʻe
Aia kekahi ʻano hana i loaʻa mai ka For, ʻo ia no … ʻē aʻe
datos = [1, 2, 3, 4, 5] for n in datos: if n == 2: break else: print('No hay 2')
Ua kū mai kēia hale ma hope o ko lākou ʻike ʻana he mea pono ia a ua nui ka poʻe e hoʻohana nei i nā ala ʻē aʻe e hoʻokō ai i kēia. No laila, kōkua lākou i nā kānaka a loaʻa i kahi code hiki ke heluhelu ʻia
no _ ma ka iterable
Ua ʻike au i kēia ma kekahi mau papahana ʻoiai ʻaʻole wau i hoʻohana.
Ke hoʻololi nei mākou i kahi mea, papa inoa, puke wehewehe'ōlelo, a me nā mea ʻē aʻe, akā ʻaʻole hoihoi mākou i ka ʻike o ia mau mea, hiki iā mākou ke hōʻike me _
Eia kekahi hiʻohiʻona:
Makemake mākou e helu i nā mea o ka papa inoa akā ʻaʻole mākou mālama i ka mea i loko, makemake mākou i kona lōʻihi.
h2=[ 'Valencia', 'Castellón', 'Alicante'] count = 0 for _ in h2: cont += 1
Ma nā pūnaewele he nui lākou e ʻōlelo ʻole e hōʻino i kēia hana. ʻAʻole maopopo iaʻu nā pōmaikaʻi e hāʻawi ʻia ana, ʻoi aku ka wikiwiki?
Manaʻo ʻia ia ma ka Harvard Introduction to Python course. Ke hoʻololi nei mākou i kahi loli akā ʻaʻole mākou e hoʻohana iā ia, kau mākou i ka undescore, e like me kā lākou ʻōlelo ʻana ma laila he Pythonic, kahi hana Python i ʻike ʻole ʻia ma nā ʻōlelo ʻē aʻe, kōkua ia i ka heluhelu ʻana ma o ka loaʻa ʻole ʻana. ʻike i ke ʻano o ia mea.
e huli ana i hope
hope no ka loop. E hana hou mai ka hope a i ka mua
Hoʻohana ia i ka hana hoʻohuli () i hoʻokomo ʻia i ka python 3
h2=[ 'Valencia', 'Castellón', 'Alicante'] for j in reversed(h2): print (j)
Looping me ʻelua mau helu, ka waiwai o ka iterable a me ka index
Me ka helu helu () hiki iā mākou ke hana me nā kuhikuhi o kahi hōʻiliʻili. No ka mea i nā manawa he nui, ma waho aʻe o ka waiwai o ka mea iterable ponoʻī, makemake mākou i kāna kuhikuhi.
h2=[ 'Valencia', 'Castellón', 'Alicante'] for j, h in enumerate(h2): print j, '-->', h2[i]
Ke hoʻomau nei ma luna o 2 papa inoa
ʻO kahi koho hoihoi ʻē aʻe ʻo ia ka zip() e maʻalahi ai kā mākou hana a e maʻalahi ai kā mākou code a hiki ke heluhelu ʻia.
h2=[ 'Valencia', 'Castellón', 'Alicante'] cod=[100, 200, 300] for j, h in zip(h2, cod): print h2, '-->', cod
Ma Python 2.x izip() ua hoʻohana ʻia e hoʻonui i kēia hana, akā ma Python 3 izip ka zip()
Ke hoʻopaʻa ʻia nei ma ke ʻano hoʻonohonoho
E hoʻokaʻaʻike ma ke ʻano o ka waiwai o ka mea ma mua o kāna kuhikuhi. hoʻohana ʻia ʻo sorted().
colors = ['rojo', 'amarillo', 'verde'] for color in sorted(colors): print color
A inā makemake mākou e hana i hope
colors = ['rojo', 'amarillo', 'verde'] for color in sorted(colors, reverse=True): print color
Hoʻonohonoho ʻano maʻamau
colors = ['rojo', 'amarillo', 'verde'] for color in sorted(colors, key=len): print color
ʻO ka waiwai Sentinel no ka loop
ʻO ka waiwai sentinel kahi waiwai e hoʻopau ai ka loop. Hōʻike pinepine ʻia ia i kahi loop loop, akā hōʻike mai ʻo Raymond Hettinger iā mākou pehea e hoʻohana ai me kahi for, ʻoi aku ka wikiwiki.
blocks = [] for block in iter(partial(f.read, 32), ''): blocks.append(block) print (block)
E hele i nā puke wehewehe ʻōlelo me ka for
ʻO nā puke wehewehe ʻōlelo he mau mea pono no ka hōʻike ʻana i nā pilina a me ka hana ʻana i nā hui.
Hiki iā ʻoe ke hele i loko o ka puke wehewehe ʻōlelo ma ke ʻano kuʻuna me ka no, akā ʻaʻole ia e hoʻihoʻi i nā ʻike āpau, ʻaʻole hiki iā mākou ke hana me nā waiwai a me nā kuhikuhi like, inā ʻaʻole mākou e hoʻomaka e hoʻohui i nā helu helu a me nā mea ʻē aʻe. mau mea.
d = {'casa': 'azul', 'coche': 'rojo', 'hombre': 'verde'} for k in d.keys(): if k.startswith('r'): del d[k]
Ma kēia ala, ma waho aʻe o ka ʻike ʻana i nā mea, hiki iā mākou ke hoʻololi i ka puke wehewehe ʻōlelo ma o ka hoʻololi ʻana i nā mea a i ʻole ka holoi ʻana iā lākou, i ka manawa like e hoʻololi ʻia ai ka loop loop.
d.keys() kāhea i nā manaʻo hoʻopaʻapaʻa a hana i kope e mālama ʻia i loko o kahi papa inoa hiki iā mākou ke hoʻololi.
E kiʻi i nā kuhikuhi a me nā waiwai ma mua o kahi mea kuʻuna a ʻo ia ka mea mua i hiki i ka noʻonoʻo no ka poʻe o mākou e hoʻomaka i ka hoʻolālā.
for k in d: print k, '-->', d[k]
E hoʻohana mākou i kēia koho wikiwiki loa
for k, v in d.items(): print k, '-->', v
mau mea () ma mua o nā mea ()
E kamaʻilio e pili ana i nā Loops ma Python na Raymond Hettinger
He wikiō kahiko akā hoʻohālikelike loa ia, kahi i nā minuke 20 mua e aʻo mai ai ʻo Raymond Hettinger iā mākou i nā ʻano like ʻole o nā puka lou ma Python a hāʻawi iā mākou i nā hiʻohiʻona o ke ʻano o ka hoʻololi ʻana i nā hale i hoʻohana nui ʻia e nā kānaka i mau hana, i mea e hiki ai ke heluhelu a maʻalahi ka loop. . code.