Special variables for the face of objects __slot__ | Python

# function: #      1. Prevent others from adding new attributes to existing instances;

#      2. Optimize memory and execution speed; #        The essence of optimization: No longer use dictionaries to store instance data, but more compact array structure; #                     Especially if you need to create a large number of objects; # attached: When inheriting a base class containing the __slot__ attribute, subclasses also define __slot__ to store their own properties . #       Otherwise, the sub-class runs more slowly; # the __slot__ property destroys the code of the underlying __DICT__ property;

Special variables for the face of objects __slot__ | Python