Variable and immutable data types

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Python Medium data type

With Python3 For example ,Python3 There are several standard data types in

Number（ Numbers ）
Bool ( Boolean value )
String（ character string ）
List（ list ）
Tuple（ Tuples ）
Sets（ aggregate ）
Dictionary（ Dictionaries ）

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The basis for dividing variable and immutable types

Variable data type

  Variable data type ：value Value change ,id The value remains the same 

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Immutable data types

 Immutable data types ：value Value change ,id The value also changes 

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How to determine whether the data type is variable or immutable

According to the concept of variable data type and immutable data type , Just change value When it's worth it , Use id() Function to view variables id Whether the value changes can tell whether this data type is variable or immutable

num = 10
print(id(num))    #1388664736


num2 = 20
print(id(num2))   #1388664736

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From the above example, we can draw a conclusion ：num Is numeric type , Numeric types are immutable data types ; Other data types use id() Function can draw a conclusion .

Variable data types contain content

Dictionary（ Dictionaries ）

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List（ list ）

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Immutable data types contain content

Number（ Numbers ）

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String（ character string ）

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Tuple（ Tuples ）

Bool( Boolean value )

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Divided by access type

 Direct access  ： Numbers 
 Sequential access  ： character string   list   Tuples 
 Map access  ： Dictionaries 

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