Python's Set function

Str

List---Lists

Tuple

DIC----Dictionary

Set

Function

-Custom functions

-built-in functions > Python-provided functions that call directly

Depth copy

Decorative Device

List characteristics: Ordered, the elements can be repeated, the dictionary key cannot be duplicated;

1.set-unordered, non-repeating sequence;

Cases:

List = [11,22,11,22]--Types of lists

DIC = {"K1": 123}--Dictionary type

A. Creating a set collection (function)

SE = {"123", "456"}--collection type

Print (Type (set))

List ()--class after addition () parentheses, which represents the invocation of the __init__ method;

list__init__, internal execution for loop (11,22,33,44) List--[11,22,33,44]

S1 = {11,22}

S2 = set ()

S3 = Set ([11,22,33,44])

B. function

s = Set () creates an empty collection;

To convert a list to a collection:

List = [11,22,11,22]

S1 = set (list)

Print (S1)

Operation Collection:

S1 = set ()

S1. Add (123)

Print (S1)

S1.clear ()

Print (S1)

S2 = {121,3132,22,11}

S1.difference (S2)

S3 = s1.symmetric_difference (S2)

Print (S3)

S1.discard (123)--Remove the specified element

S1.pop ()--random removal of an element

ret = S1.pop ()---Remove an element and assign the element to RET

S1.update (list)--iterate to add elements

Python's Set function