我如何解决这个功能？

Question

This is the assignment ive been given and im having trouble making it work properly. But it says that im having an error in the last line at "print(total)" - but im not sure what is wrong here. Does someone know the answer to this ?

Change the code below to create a function that calculates the cost of a trip. It should take the miles, milesPerGallon, and pricePerGallon as parameters and should return the cost of the trip.

miles = 500
milesPerGallon = 26
numGallons = miles / milesPerGallon
pricePerGallon = 3.45
total = numGallons * pricePerGallon
print(total)  

The code ive come to so far is this :

def costOfTrip(miles,milesPerGallon,pricePerGallon):
    miles = 500
    milesPerGallon = 26
    numGallons = miles / milesPerGallon
    pricePerGallon = 3.45
    total = numGallons * pricePerGallon
    print(total)

Answer 1

depends on where you're writing the code, it may be print total . But just swap out the print for a return, so it would be lie:

return total

Also, you're always assigning 500 to miles, 26 to imlesPerGallon and 3.45 to pricePerGallon. Try this out:

def costOfTrip(miles,milesPerGallon,pricePerGallon=3.45):
    numGallons = miles / milesPerGallon
    total = numGallons * pricePerGallon
    return total

This means that you have to pass in the miles , milesPerGallon and the pricePerGallon parameters. The pricePerGallon is optional and defaults to 3.45 . You can then call the function like this:

total = costOfTrip(500,26)
print(total)

Answer 2

I think it should look like:

def costOfTrip(miles, milesPerGallon, pricePerGallon):
    # miles, milesPerGallon and pricePerGallon are received args 
    numGallons = miles / milesPerGallon
    total = numGallons * pricePerGallon
    return total

Usage example

cost = costOfTrip(500, 26, 3.45)
print(cost)

Answer 3

You have to pass the values as arguments to function to get the values calculated and returned. you can refer below code.

def costOfTrip(miles,milesPerGallon,pricePerGallon):
    numGallons = miles / milesPerGallon
    total = numGallons * pricePerGallon
    return total

miles = 500
milesPerGallon = 26
pricePerGallon = 3.45

print(costOfTrip(miles,milesPerGallon,pricePerGallon))

Output

66.34615384615385