None and Null in Python

One, Python object

To understand this, first understand the Python object:

A Python object has three attributes: Identity, type, value.

The three attributes are assigned when the object is created. Only values can be changed, others are read only.

The type itself is also an object.

Two, null and none

is a special type of Python, the null object or the None type, which has only one value of none.

It does not support any operations and does not have any built-in methods.

None and any other data types compare forever to return false.

None has its own data type Nonetype.

You can copy none to any variable, but you cannot create other Nonetype objects.


Copy Code
>>> type (None)
<class ' Nonetype ' >
>>> None = = 0
False
>>> None = = "'
False
>>> None = = None
True
>>> None = = False
False

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