array = list()
def func():
    if array==None:
        pass
    else:
        i = 0
        while array[i]!=None:
            pass
func()
while array[i]!=None:
IndexError: list index out of range

>>> array = list()
>>> array
[]
>>> none=None
>>> print(none)
None
>>> array==none
False

>>> not array
True