def old_is_prime(num):
    # You only need to go up to sqrt(num) rather than num/2
    for i in range(0, num//2):
        # You're only checking for divisibility by two
        if (num % 2) == 0:
            return False
        # You don't need an else; after the first iteration, the function ALWAYS returns
        else:
            return True
    # Instead return after the loop goes through every case

# Improved version
def new_is_prime(num):
    if num <= 2:
        return False
    for i in range(2, int(num ** (1/2)) + 1):
        if num % i == 0:
            return False
    return True

# Compact and functional approach
def compact_is_prime(num):
    return all(num % i != 0 for i in range(2, int(num ** .5) + 1))

# Don't ask the user to pick the range, you should check it in the function
num = int(input("Input an integer greater than 1: "))

if compact_is_prime(num):
    print("{:d} is a prime".format(num))
else:
    print("{:d} is not a prime".format(num))