what is wrong with this 'if' statement!?

[neshom_imilas]

hello!
I am new to coding and I have 0 experience.
I've started learning just yesterday! I was writing something to take a full name and sort out first and last name. but I have a problem.

while True:
    full_name = input('What is your full name!? ')
    first_and_last_name = full_name.split(' ')
    first_name = first_and_last_name[0]
    number_of_name_segments = len(first_and_last_name)
    full_name_length = len(full_name)
    numbers = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
    numbers_in_name = False
    for letters in full_name:
        if letters in numbers:
            numbers_in_name = True
            break
    if numbers_in_name:
        print('Names can\'t have numbers in them')
    if full_name_length < 6:
        print('Your name is too short.')
    if full_name_length > 50:
        print('Your name is too long.')
    if number_of_name_segments <= 1:
        print('Please enter your full name.')
    if number_of_name_segments == 2:
        last_name = first_and_last_name[-1]
        middle_name = 'none'
        break
    if number_of_name_segments == 3:
        last_name = first_and_last_name[-1]
        middle_name = first_and_last_name[1]
        break
    if number_of_name_segments > 3:
        print('Only enter your first and middle and last name.')
print(f'Hello {first_name} {middle_name} {last_name} welcome abroad!')

this is my code. the problem is when I enter numbers instead of my name the code doesn't go back to the top. it just accepts the numbers as a name!!!
but if I put less than 6 characters it won't accept and it will go back to the top!
why is that?!what is the difference between these two lines of code!?
Thank you please help me learn

[bowlofred]

I think you are misinterpreting what is happening.

Your first 4 tests (between lines 13 and 20) don't do anything except print some data to the screen. They don't stop the program or affect it. You'd need to have a break or some other logic for them to do that.

The only tests that stop the loop are the next 2 (number of segments is 2 or 3). Everything else is just a warning. So putting in less than 6 characters is still accepted, as long as there are 2 or 3 segments.