Intermediate · Functions · 111 of 264
Primes up to n
Print all prime numbers up to and including n, on one line.
Input: a whole number n (n >= 2). Output: the primes, separated by spaces.
Examples
Input
20
Output
2 3 5 7 11 13 17 19
Input
2
Output
2
Input
50
Output
2 3 5 7 11 13 17 19 23 29 31 37 41 43 47
One more test checks other inputs when you press Check.
Stuck? The idea behind functions
A function, made with def, gives a name to a piece of code, so it can be used again: its parameters are the values it is given, return hands an answer back.
A function that returns lets the caller decide what to do with the answer: print it, compare it, use it in a sum.
def is_even(n):
return n % 2 == 0
print(is_even(4))
print(is_even(7))Watch for: print inside a function is not return: the caller gets None. And the code after return in the same block never runs.