I'm new to python, If the number from the list is less than 18, then the number is not printed

#Code
x = [17, 15, 18, 21, 5, 6]
   for y in x:
        if y < 18:
            y = x.copy()
            print (y)    

Im want:
18 21
but result:
17, 15, 18, 21, 5, 6
17, 15, 18, 21, 5, 6
17, 15, 18, 21, 5, 6
17, 15, 18, 21, 5, 6

>Solution :

Iterate over the values, if the value is valid (>=18) keep it in an other list, at the end print them

x = [17, 15, 18, 21, 5, 6]
valid_values = []
for y in x:
    if y >= 18:
        valid_values.append(y)
print(valid_values)  # [18, 21]

With list-comprehension

valid_values = [y for y in x if y >= 18]