创建 python function 以返回值

Question

I have written a function called "adjust", so what it needs to do is to take user input from 0 to 9 and to retune either 0,5 or 10.

My function has come across a syntax error when it runs until "elif", But I can't figure out what I did wrong. This is what I have now ( I try to use control K to post the code but if keep giving me an error)

cents = []
def adjust(cents):
    c=0
    for i in cents:
        x=cents.index(i)
        if(i==1 or i==2): 
            j=0
            elif(i==3 or i==4 or i==6 or i==7): 
                j=5
                elif(i ==8 or i==9):
                    j = 10
                    else:
                        j=i
                        return cents


n=int(input("Enter a number of cents between 0 and 9:))
#haven't figure out how to put the user input into my function

The example output would be:

input 1, output 0 input 4, output 5 input 8, output 10

Answer 1

The reason for that is indentation. In Python, indentation is used to indicate the scope of the operation. In your case, your elif is inside the if and thus raises a Syntax error, as there was no if before it in the same scope.

Simply fixing your indentation will solve the issue. However, your code could also be written a bit cleaner (and I am assuming you want to return the modified versions, not the originals), so my version would be:

def adjust(cents):
    # Make copy of provided cents to modify
    adj_cents = list(cents)

    # Loop over all cents and round all values to nearest 5
    for i, x in enumerate(adj_cents):
        if x in (1, 2): 
            adj_cents[i] = 0
        elif x in (3, 4, 6, 7): 
            adj_cents[i] = 5
        elif x in (8, 9):
            adj_cents[i] = 10

    # Return adj_cents
    return(adj_cents)


n=int(input("Enter a number of cents between 0 and 9:))
#haven't figure out how to put the user input into my function

If you finish writing your script, you will be able to provide an iterable of cents you want to adjust to the function, which will return you the adjusted ones. No need to call it iteratively.