could someone explain this code for me(why it prints all the even numbers between 2 and 10)

Question

for i in range(10):
if not i % 2 == 0:
print(i+1)

Answer 1

range(10) creates a list of integers starting from 0 to 9. The for-each loop iterates through this list of integers, and for those which are not even (not i%2==0), we print the result of this integer being incremented by 1 (print(i+1)).

You can handtrace the code to get the results.

not 0 % 2 == 0
false

not 1 % 2 == 0
true
print(1+1)
2

not 2 % 2 == 0
false

not 3 % 2 == 0
true
print(3+1)
4

...

not 9 % 2 == 0
true
print(9+1)
10

By the complete sequence, you should get

2
4
6
8
10

Answer 2

A shorter way to write 'if not i % 2 == 0'
is 'if i % 2'.

'if x' is the same as 'if x == True'.
Since 0 is False and all other numbers are True, 'if x' means 'if x is any number other than 0' , i.e. 'if x != 0', which is the same as 'if not x == 0'. So here,
'if i % 2' is the same as 'if not i % 2 == 0'.

Generally, writing Python code that is simple and direct is considered 'Pythonic', so saying 'if i % 2' is more Pythonic than saying 'if not i % 2 == 0'.