Python: .format() and @ symbol

Question

def foo(fn):
def wrap():
return ">{}".format(fn())
return wrap
@foo
def something():
return "result"
print (something()). #outputs >result
The format() method inserts the specified value(s) inside the string's placeholder { }.
Question 1: Is the specified value in this case > or fn() ?
Question 2: What does the @ symbol do?
Question 3: What does function foo have to do with function something?
Question 4: Is there any other concept I need to understand to be able to answer this question?

Answer 1

1. yeah, but fstrings are a lot more useful
2., 3. (and mabey 4)i cant explain it better:
https://www.sololearn.com/learn/JUMP_LINK__&&__Python__&&__JUMP_LINK/2463/

Answer 2

1.Obviously the specified value is fn() in this case ,">" is just a symbol or string ,whatever value is passed to format replaces the {}
For 2,3,4 Slick already provided link