logo

Betingede uttrykk i Python

Pythons betingede utsagn utfører forskjellige beregninger eller operasjoner i henhold til om en bestemt boolsk tilstand vurderes som sann eller usann. I Python omhandler IF-utsagn betingede utsagn.

Vi lærer hvordan du bruker betingede utsagn i Python i denne opplæringen.

java int til char

Hva er Python If Statement?

For å ta avgjørelser, bruk if-setningen i Python. Den har en mengde instruksjoner som bare utføres når if-setningens betingelse er oppfylt. Den ekstra else-setningen, som inkluderer noen instruksjoner for else-setningen, kjøres hvis if-betingelsen er usann.

Pythons if-else-setning brukes når du ønsker å tilfredsstille en setning mens den andre er usann.

Python-syntaks for if-setningen:

 if Statement else Statement 

Kode

 # Python program to execute if statement a, b = 6, 5 # Initializing the if condition if a > b: code = 'a is greater than b' print(code) 

Produksjon:

 a is greater than b 

Hvordan bruke den andre betingelsen?

'else-betingelsen' brukes vanligvis når man bedømmer en påstand basert på en annen. Hvis betingelsen nevnt i if-kodeblokken er feil, vil tolken utføre den andre kodeblokken.

Kode

 # Python program to execute if-else statement a, b = 6, 5 # Initializing the if-else condition if a <b: code="a is less than b" print(code) else: print('a is greater than b') < pre> <p> <strong>Output:</strong> </p> <pre> a is greater than b </pre> <h2>When the else Statement does not Work</h2> <p>There could be a lot of situations where your &apos;otherwise condition&apos; doesn&apos;t produce the desired outcome. Due to a flaw in the program&apos;s logic, it will print the incorrect result. This typically occurs when there are more than two statements or conditions in a program.</p> <p>An illustration will make this notion easier for you to grasp.</p> <p>Since both variables, in this case, are identical (9, 9), the program&apos;s output that &apos;x is greater than y&apos; is FALSE. This is because it evaluates the first condition, or the if expression in Python, then prints the next condition (the else statement) by default if the first condition fails. The following step will examine how to fix this mistake.</p> <p> <strong>Code</strong> </p> <pre> # Python program when else condition does not work a, b = 9, 9 # Initializing the if-else condition if a <b: code="a is less than b" else: print(code) < pre> <p> <strong>Output:</strong> </p> <pre> a is greater than b </pre> <h2>How to use the elif Condition?</h2> <p>We can employ the &apos;elif&apos; clause to fix the issue caused by the &apos;else condition&apos; made earlier. You can instruct the software to print the third condition or alternative when the first two conditions fail or are erroneous by using the &apos;elif&apos; condition.</p> <p> <strong>Code</strong> </p> <pre> # Python program to show how to use elif condition a, b = 9, 9 # Initializing the if-else condition if a <b: code="a is less than b" elif a="=" b: else: print(code) < pre> <p> <strong>Output:</strong> </p> <pre> a is equal to b </pre> <h2>Python Nested if Statement</h2> <p>The following example demonstrates nested if Statement Python</p> <p> <strong>Code</strong> </p> <pre> # Python program to show the nested if-else conditions A = 100 B = 200 C = 300 # Initializing the if-else conditions if B &gt; A: if B &gt; C: print(&apos;B is the largest number&apos;) else: if A &gt; B: if A &gt; C: print(&apos;A is the largest number&apos;) elif C &gt; A: if C &gt; B: print(&apos;C is the largest number&apos;) else: print(&apos;All numbers are equal&apos;) if B % C == 0: if A % C == 0: print(&apos;C is a common factor of A and B&apos;) </pre> <p> <strong>Output:</strong> </p> <pre> C is the largest number </pre> <hr></b:></pre></b:></pre></b:>

Når den andre erklæringen ikke fungerer

Det kan være mange situasjoner der din 'ellers tilstand' ikke gir det ønskede resultatet. På grunn av en feil i programmets logikk, vil det skrive ut feil resultat. Dette skjer vanligvis når det er mer enn to utsagn eller betingelser i et program.

En illustrasjon vil gjøre dette lettere for deg å forstå.

Siden begge variablene, i dette tilfellet, er identiske (9, 9), er programmets utgang at 'x er større enn y' FALSE. Dette er fordi den evaluerer den første betingelsen, eller if-uttrykket i Python, og skriver deretter ut neste betingelse (else-setningen) som standard hvis den første betingelsen mislykkes. Det følgende trinnet vil undersøke hvordan du kan fikse denne feilen.

Kode

 # Python program when else condition does not work a, b = 9, 9 # Initializing the if-else condition if a <b: code="a is less than b" else: print(code) < pre> <p> <strong>Output:</strong> </p> <pre> a is greater than b </pre> <h2>How to use the elif Condition?</h2> <p>We can employ the &apos;elif&apos; clause to fix the issue caused by the &apos;else condition&apos; made earlier. You can instruct the software to print the third condition or alternative when the first two conditions fail or are erroneous by using the &apos;elif&apos; condition.</p> <p> <strong>Code</strong> </p> <pre> # Python program to show how to use elif condition a, b = 9, 9 # Initializing the if-else condition if a <b: code="a is less than b" elif a="=" b: else: print(code) < pre> <p> <strong>Output:</strong> </p> <pre> a is equal to b </pre> <h2>Python Nested if Statement</h2> <p>The following example demonstrates nested if Statement Python</p> <p> <strong>Code</strong> </p> <pre> # Python program to show the nested if-else conditions A = 100 B = 200 C = 300 # Initializing the if-else conditions if B &gt; A: if B &gt; C: print(&apos;B is the largest number&apos;) else: if A &gt; B: if A &gt; C: print(&apos;A is the largest number&apos;) elif C &gt; A: if C &gt; B: print(&apos;C is the largest number&apos;) else: print(&apos;All numbers are equal&apos;) if B % C == 0: if A % C == 0: print(&apos;C is a common factor of A and B&apos;) </pre> <p> <strong>Output:</strong> </p> <pre> C is the largest number </pre> <hr></b:></pre></b:>

Hvordan bruke elif Condition?

Vi kan bruke 'elif'-klausulen for å fikse problemet forårsaket av 'else-tilstanden' som ble gjort tidligere. Du kan instruere programvaren til å skrive ut den tredje betingelsen eller alternativet når de to første betingelsene mislykkes eller er feil ved å bruke 'elif'-betingelsen.

Kode

 # Python program to show how to use elif condition a, b = 9, 9 # Initializing the if-else condition if a <b: code="a is less than b" elif a="=" b: else: print(code) < pre> <p> <strong>Output:</strong> </p> <pre> a is equal to b </pre> <h2>Python Nested if Statement</h2> <p>The following example demonstrates nested if Statement Python</p> <p> <strong>Code</strong> </p> <pre> # Python program to show the nested if-else conditions A = 100 B = 200 C = 300 # Initializing the if-else conditions if B &gt; A: if B &gt; C: print(&apos;B is the largest number&apos;) else: if A &gt; B: if A &gt; C: print(&apos;A is the largest number&apos;) elif C &gt; A: if C &gt; B: print(&apos;C is the largest number&apos;) else: print(&apos;All numbers are equal&apos;) if B % C == 0: if A % C == 0: print(&apos;C is a common factor of A and B&apos;) </pre> <p> <strong>Output:</strong> </p> <pre> C is the largest number </pre> <hr></b:>

Python Nested if Statement

Følgende eksempel viser nestet if Statement Python

Kode

 # Python program to show the nested if-else conditions A = 100 B = 200 C = 300 # Initializing the if-else conditions if B &gt; A: if B &gt; C: print(&apos;B is the largest number&apos;) else: if A &gt; B: if A &gt; C: print(&apos;A is the largest number&apos;) elif C &gt; A: if C &gt; B: print(&apos;C is the largest number&apos;) else: print(&apos;All numbers are equal&apos;) if B % C == 0: if A % C == 0: print(&apos;C is a common factor of A and B&apos;) 

Produksjon:

 C is the largest number