python 3.x - Conditional statement with empty string -

why '' , not '123' evaluate '' instead of false, not '123' , '' evaluates false in python 3.4.3?

the logical and/or operators stop evaluating terms (short-circuit) answer decided.

examples and

>>> '' , not '123' '' 

the first 1 false, and short-circuited , first 1 returned.

>>> not '123' , '' false 

not '123' returns false. since false, and short-circuited , result of not '123' 1 returned.

for same reason, following returns zero:

>>> 0 , '123' 0 

and following returns []:

>>> [] , '123' [] 

examples or

>>> '' or '123' '123' >>> not '123' or 'hi' 'hi' >>> '123' or 'hi' '123' 

documentation

this behavior specified in the documentation where:

• x or y defined if x false, y, else x

• x , y defined if x false, x, else y

• not x defined if x false, true, else false