Why does python use 'else' after for and while loops?

Question

I understand how this construct works:

for i in range(10):
    print(i)

    if i == 9:
        print(\"Too big - I\'m         


        

Answer 1

for i in range(3):
    print(i)

    if i == 2:
        print("Too big - I'm giving up!")
        break;
else:
    print("Completed successfully")

"else" here is crazily simple, just mean

1, "if for clause is completed"

for i in range(3):
    print(i)

    if i == 2:
        print("Too big - I'm giving up!")
        break;
if "for clause is completed":
    print("Completed successfully")

It's wielding to write such long statements as "for clause is completed", so they introduce "else".

else here is a if in its nature.

2, However, How about for clause is not run at all

In [331]: for i in range(0):
     ...:     print(i)
     ...: 
     ...:     if i == 9:
     ...:         print("Too big - I'm giving up!")
     ...:         break
     ...: else:
     ...:     print("Completed successfully")
     ...:     
Completed successfully

So it's completely statement is logic combination:

if "for clause is completed" or "not run at all":
     do else stuff

or put it this way:

if "for clause is not partially run":
    do else stuff

or this way:

if "for clause not encounter a break":
    do else stuff