如何从我的 output 中排除引号？

Question

I need to write a function is_prime , to determine if n is a prime number, and if not I have to show the factors beginning with the smallest possible factor.

It works however I need to exclude the quotation marks in the output otherwise I don't get any points for my homework.

def is_prime(n):
    pass

    if n > 1:
       for i in range(2,n):
           if (n % i) == 0:
               return(n,'is not a prime number', '(', i,'*',n//i,'=', n, ')')

               break
       else:
           return(n,'is prime')

    else:
       return(n,'is not a prime number')

print(is_prime(12))

Answer 1

Your problem is you are returning a list when you should return a string, you should use str.format() to return a string:

https://www.digitalocean.com/community/tutorials/how-to-use-string-formatters-in-python-3

Also you do not need your 'break' nor 'else', because when you execute a return statement, your function end.

So if you found a divisor of n, you get into the return statement and the code after that is not executed.

def is_prime(n):
    if n > 1:
        for i in range(2, n):
            if (n % i) == 0:
                return('{n} is not a prime number ({i} * {q} = {n})'.format(n=n, i=i, q=n//i))
        return('{n} is prime'.format(n=n))
    return('{n} is not a prime number'.format(n=n))

print(is_prime(15))

Answer 2

Instead of using comma (,) in your return statement, replace it with plus sign (+) and convert all your number value into string using str() function.

def is_prime(n):
    pass

    if n > 1:
       for i in range(2,n):
           if (n % i) == 0:
               return(str(n) + ' is not a prime number ' + '(' + str(i) + '*' + 
str(n//i) + '=' + str(n) + ')')

               break
       else:
           return(n + 'is prime')

    else:
       return(n + 'is not a prime number')

print(is_prime(12))