IiNkcazo zePython ezinemiqathango - Ukuba, Else kunye no-Elif

Kule tutorial sijonga indlela yokusebenzisa if | else kunye elif Iingxelo kwiPython.

Xa ufaka ikhowudi kulo naluphi na ulwimi, kukho amaxesha apho kufuneka sithathe isigqibo kwaye senze ikhowudi ethile esekwe kwisiphumo sesigqibo.

KwiPython, sisebenzisa if ingxelo yokuvavanya imeko.

IPython Ukuba Ingxelo

Is syntax se if Isiteyitimenti kwiPython yile:

if condition:
statement

Nika ingqalelo ngakumbi kwi-semi-colon : kwaye i ulwaziso .

Sisebenzisa abaqhubi abanengqiqo ukuvavanya imeko. Abasebenza ngokusengqiqweni zezi:

• Ukulingana: a == b
• Abangalingani: a != b
• Ngaphantsi kwe: a < b
• Ngaphantsi okanye kulingana nokuba: a <= b
• Kukhulu kune: a > b
• Kukhulu kunokuba okanye kulingana nokuthi: a >= b

Ikhowudi elandelayo if Isiteyitimenti senziwa kuphela ukuba imeko ivavanya ukuya true.

Umzekelo if Ingxelo kwiPython:

password = 'Hello' if len(password) < 6:
print('password too weak - should be at least 6 characters')

Iziphumo:

password too weak - should be at least 6 characters

Kule khowudi ingentla, sivavanya ubude begama eligqithisiweyo. Imeko kukuba, ubude akufuneki bube ngaphantsi koonobumba aba-6 ubude.

Oku kuchazwe ngumsebenzisi ongaphantsi komsebenzisi <.

Kuba umtya 'Molo' ungaphantsi koonobumba aba-6, imeko ke ivavanya ukuya yinyani Kungoko sibona ingxelo eprintiweyo.

IPython Ukuba… Enye ingxelo

Ukuba iziphumo zovavanyo zibubuxoki kwaye Sifuna ukuthatha inyathelo kwisiphumo, emva koko sibandakanye else ingxelo.

Is syntax se if...else ingxelo ibonakala:

if condition:
statement_1 else:
statement_2

Ke, ngokuqhubeka nomzekelo omnye ongentla, ukuba sifuna ukwazisa umsebenzisi ukuba igama labo eliyimfihlo lidibene nobude obufunekayo, siyibeka kwi else ibhloko.

Umzekelo:

password = 'Mission' if len(password) < 6:
print('password too weak - should be at least 6 characters') else:
print('your password was accepted')

Iziphumo:

your password was accepted

Kule meko, igama elithi 'iMishini' linabalinganiswa abasi-7 ngoko ke if imeko ivavanya ubuxoki. Kuba sine else ibhlokhi, emva koko eyesibini print() ingxelo iyenziwa.

Ukuphinda-phinda ukuba… Else ngoElif

Xa inkqubo ifuna ukuphatha ngaphezulu kwamatyala amabini, kufuneka sisebenzise ezininzi if kunye else iibhloko. Igama eliphambili elif kuthetha enye into ukuba.

Umzekelo, sinenkqubo ekufuneka ichonge uhlobo lonxantathu ngokusekwe kwigalelo eli-3 elipheleleyo.

• Ukukala unxantathu yindawo apho omathathu amacala anobude obahlukeneyo
• Unxantathu weIsosceles unamacala amabini anobude obulinganayo
• Unxantathu olinganayo yindawo apho onke amacala alinganayo

a = 5 b = 5 c = 5 if a != b and b != c and a != c:
print('This is a scalene triangle') elif a == b and b == c:
print('This is an equilateral triangle') else:
print('This is an isosceles triangle')

Iziphumo:

This is an equilateral triangle

Lo mzekelo ubonakalisa indlela yokusingatha ngaphezulu kwamatyala amabini. Njengangaphambili, khumbula : kunye ne-indent.

Akukho mda kwinani le elif s esinokuthi silisebenzise. Kufuneka kubekho enye kuphela _ _ + _ | Isiteyitimenti esisebenza njengokubamba konke. Ukuba zonke else Iingxelo ziyasilela, emva koko if ingxelo iyenziwa.

I-Python Ternary Operator (Shorthand Ukuba… Enye into)

Ukuba sine else ibhloko, sinokusebenzisa i-ternary operator kwaye sibhale if...else block kumgca omnye.

Is syntax yile:

if...else

Umzekelo:

condition_if_true if condition else condition_if_false

Iziphumo:

a = 100 b = 200 print('A') if a > b else print('B')

Isiphelo

• I B kunye if...else iingxelo zilawula ukuhamba kwenkqubo.
• Inkcazo if kwinkqubo isetyenziselwa ukwenza izigqibo.
• Inkcazo ukuba ingxelo ivavanywa ngokwezi meko zichaziweyo.
• Enye ibhloko inokuqhotyoshelwa nengxelo ukuba iyenziwa xa imeko ingeyonyani.
• Enye ibhlokhi ayinakubakho nengxelo.
• Iingxelo ze-elif zinokuqhotyoshelwa kunye nengxelo ukuba kukho iimeko ezininzi.