Why this code print 1 in this code ?

Question

Based on which logic this code results 1 ?

As inside parentheses in first line is blank having 1 as code result is logical, but I changed inside parentheses to 2 , 3 or string ("hi"), but still received foo is equal to None !!!

https://code.sololearn.com/c83XDykgMu7O/?ref=app

Answer 1

I changed inside parentheses in this code but still receive None (1 will be printed) !!

https://code.sololearn.com/c38vU064152j/?ref=app