Python value delivery problem and memory management mechanism

1) Value transfer problem

Whether the python is "value passing" or "reference passing" depends primarily on the object being mutable. 1) Function Reference: • Basic data type: int, float, str; Ganso is a non-mutable object, and a copy of "original value" is passed. The list, dictionary, class, class instances are mutable objects, and the variable copy (a=b) in the variable copy Python is passed as the same as Kind of truth, immutable objects are actually copied, whereas mutable objects simply pass a "reference" example: a = 1 B = A, at which time changing the value of a does not change the value of B

2) Memory mechanism

1) variable values are stored in memory • Basic data types: int, str, float, etc., the same value is assigned to different variables, the memory address is consistent;        • Lists, Ganso, dictionaries, the same values are assigned to different variables, the memory address is an example of inconsistency: a = 1 b = 1 ID (a) =id (b) This is a = [up] b = [up] ID (a) = ID (b) This is not true 2) memory management mechanism • Reference count: Trace objects in memory when an object is created, a reference count is created, and when the object is no longer needed, the object's reference count is 0 o'clock, and it is garbage collected. • Memory pool: not currently discussed

This article from "Kong Love to Eat fish" blog, declined reprint!

Python value delivery problem and memory management mechanism