what is difference between [None] and [] in python? [duplicate]

Answer 1

You want to use None to imply that there is no valid object. You want to use [] to imply an object that is of type list and has no elements.

[None] is a list with one element which is None

>>>c= []  # This is a new list object
>>>d= []  # This is another new list object

In Python , x is y is used to check whether x and y are the same objects. Here, c and d point to different list objects. so,

>>>print c is d
False

is expected.

On the other hand,

>>>c= []  # This is a new list object
>>>d = c  # This is the same object as c
>>>print c is d
True

Here, a and b are primitives, not objects

>>>a= 1
>>>b=1

So, this is expected:

print a is b
True