Escape indentation

[Gribouillis]

Wonder what is the principle idea behind the scene to be force to create a new variable to escape the indent.

Your design is wrong from the start because the role of function is_prime_v1() is not well defined. It tells whether n is prime by returning a boolean, and at the same time, it appends items to the prime list and returns the value of n. These are too many tasks for a single function.

def is_prime_v1(n):
    """Return a boolean indicating if integer n is prime"""
    if n == 1:
     return False
     
    for d in range(2, n):
        if n % d == 0:
            return False
    return True

prime = []
for n in range(1,21):
  if is_prime_v1(n):
    prime.append(n)

print(prime)

Output:
[2, 3, 5, 7, 11, 13, 17, 19]