Python/list comprehensions and multiples

Question

Hi all,

Could someone give me a steer as to where I’m going wrong here. Trying to find all the multiples of both 3 & 5 up to and input interger;

x = int(input())
#your code goes here

numbers = list(range(0, x)

mutiples = [number for number in numbers if number % 3 == 0 and number % 5 == 0]

print(multiples)

Answer 1

You forgot a parenthesis. It should be:
numbers = list(range(0, x))
Also notice that the list multiples will include 0 too (since 0 % *any number* is equal to 0) and that number will be included only if it is divisible both by 5 and 3.
You could write:
multiples = [number for number in numbers if number != 0 if number % 3 == 0 or number % 5 == 0]
Edit: I thought it should have included numbers divisible either by 3 or 5. I just noticed my mistake

Answer 2

Any number fully divisible by both 3 and 5 are multiples of 15. So it might be considerable to utilize the stepping parameter of `range()` function, and start the range from 15.

multiples = [ number for number in range( 15, x, 15 ) ]

Answer 3

Thanks Ciro Manuel Penna ! 2 hours pickle for a forgotten parenthesis grrrrr

Answer 4

Mirielle[ Exams ] for divisibility "x % y == 0" is more expressive / clearer than "not x % y" imo. Just an opinion, but I read the first variant way more often. And including the "not" they differ in length only by a single space.

[x for x in y if x > 0 and x % 3 and x % 5]
return numbers not divisible by 3 or 5, so that may serve as example; mistakes are not as easy to spot.

range starts at 0 by default, so range(0, x) can be shortened to range(x)

Answer 5

I realize this is an *ancient* question, and you now are likely Lord(ess) of Python, but just for the sake of others who might be equally curious:
Correct me if I'm wrong in general practice, but II don't see the need for the extra line to establish range, as one can use simply the following (*changed variables to use your designations for clarity*):
______________
x = int(input())
#Take input. Output a list of all numbers up to input that are multiples of both 3 and 5.

multiples = [number for number in range(0,x) if number % 3 == 0 and number % 5 == 0]

print(multiples)
______________
So basically, including the range() within the primary statement that defines 'multiples' following the for loop works just fine as well (and gives you the appropriate outputs).

Now, PLEASE (ANYONE) correct me if this is bad practice, as I'm pretty new to Python, and I'm not sure if this is the sort of bad habit one shouldn't establish or whether this is actually not problematic at all (the inclusion of the range()) within the same line that defines 'multiples').

I always figure that the fewer variables used the better in cases like these, especially when you're not returning a value or otherwise have an additional use for the variable replaced (though please, again, anyone, correct me if I'm wrong).

Thanks for asking the question and starting the conversation!!!

Answer 6

num = input("enter a number: ")
l = [number for number in range(0,int(num)+1) if number % 3 == 0 and number % 5 == 0]
print(l)

# no need to declare range as list!

Answer 7

This get you all cases green:

x = int(input())
#your code goes here1
l = [number for number in range(0,int(x)+1) if number % 3 == 0 and number % 5 == 0]
print(l)

Ask if u have some questions!