trying to understand a string literal in a basic server program

[deanhystad]

iimport socket
HEADERSIZE=10
msg = "Welcome to the server!"
print(len(msg))
x = f'{len(msg):<10{HEADERSIZE}}'+msg
y = f'{len(msg):<1010}'+msg
print(len(x), len(y), x == y)

Output:
1032 1032 True

10{HEADERSIZE} ends up as 1010. The resulting string is 1032 characters long. 1010 character for the message length and padding and 22 characters for the message.

If I print x it looks like this:

Output:
22




     Welcome to the server!

This is "22" followed by 1008 blanks and then "Welcome to the server!"