Logical operators in Python

Question

While reading about logical operators in python, I came across the following expressions:

5 and 1 

output: 1

5 or 1 

output: 5

Can anyone explain how this is working?
I know that the operands of the logical operators are Boolean

Answer 1

that is well documented:

x or y      if x is false, then y, else x 
x and y     if x is false, then x, else y 

both short-circuit (e.g. or will not evaluate y if x is truthy).

the documentation also states what is considered falsy (False, 0, None, empty sequences/mappings, ...) - everything else is considered truthy.

a few examples:

7 and 'a'             # -> 'a'
[] or None            # -> None
{'a': 1} or 'abc'[5]  # -> {'a': 1}; no IndexError raised from 'abc'[5]
False and 'abc'[5]    # -> False; no IndexError raised from 'abc'[5]

note how the last two show the short-circuit behavior: the second statement (that would raise an IndexError) is not executed.

your statement that the operands are boolean is a bit moot. python does have booleans (actually just 2 of them: True and False; they are subtypes of int). but logical operations in python just check if operands are truthy or falsy. the bool function is not called on the operands.

---

the terms truthy and falsy seem not to be used in the official python documentation. but books teaching python and the community here do use these terms. there is a discussion about the terms on english.stackexchange.com and also a mention on wikipedia.