Python Equality Gothas

2024-03-19

Gabriel Montpetit

I was debugging some code and I found a few gotchas with equality in Python. I thought I would add them here for posterity:

when x is 0.0:

not x is True
x is None is False

when x is 0:

not x is True
x is None is False

when x is 1:

not x is False
x is None is False

when x is 1.0:

not x is False
x is None is False

when x is None:

not x is True
x is None is True

when x is '':

not x is True
x is None is False

when x is False:

not x is True
x is None is False

when x is True:

not x is False
x is None is False

when x is []:

not x is True
x is None is False

when x is {}:

not x is True
x is None is False

when x is ():

not x is True
x is None is False

when x is set():

not x is True
x is None is False