Weird boolean evaluation in python 3.8

Question

While trying to debug an issue, I hit some weird boolean evaluation happening in python. Below is the sample shell result.

In [4]: True or False and False
Out[4]: True

In [5]: False or True and False
Out[5]: False

What exactly is happening here. Shouldn't both evaluate to the same result?

Answer 1

and binds tighter than or, so what you're writing is actually

In [4]: True or (False and False)
Out[4]: True

In [5]: False or (True and False)
Out[5]: False

Answer 2

and takes precedence over or. See what happens when we evaluate the and first?

>>> (True or False and False) == (True or False)
True
>>> (False or True and False) == (False or False)
True