1. Python basic Object Type----number

First thing to remember: object thinking: All things are objects!

• Accurate Description python an object that requires "identity, type, value" from three dimensions.

>>> 520

520

>>> 55555555555555555555555555555

55555555555555555555555555555L

>>> 3.1415926

3.1415926

>>>

int integers : 520

Long large integers : Python automatically converts large integers and displays an l at the end;

float floating point number: 3.1415926

two built-in functions (Build-in function):

Identity ID (): View the object memory address.

>>> ID (520)

38401608L

>>> ID (55555555555555555555555555555)

38334056L

>>> ID (3.1415926)

32795904L

>>>

Types type (): View Object types.

>>> Type (520)

<type ' int ' >

>>> type (55555555555555555555555555555)

<type ' Long ' >

>>> type (3.1415926)

<type ' float ' >

>>>

The value object itself, the above example is a numeric value.

object has type, variable no type!

• Variable:

>>> x=520

>>> x

520

>>> x=110

>>> x

110

>>>

X is a variable, assign a value of 520 to it, and then assign a value of 110 to it; X is like a label;

x as a variable, no type;

Type (x) returns the value of the x corresponding to the kind;

>>> x=110

>>> type (x)

<type ' int ' >

>>> x=55555555555555555555555555555

>>> type (x)

<type ' Long ' >

>>> x=3.1415926

>>> type (x)

<type ' float ' >

>>>

• Arithmetic

Add +, minus-, multiply *, divide/, computer and math arithmetic rules.

>>>

2

>>> 1+1.0

2.0

>>> 1.0+1.0

2.0

>>> type (1.0+55555555555555555555555555555)

<type ' float ' >

>>>

Need to note:

Float floating-point +int integer =float floating-point type

float float type +long long integer =float floating point type

• Integer overflow problem:

Python solves this problem for us, supporting an "infinite precision" integer, as follows:

>>> 2**1000

10715086071862673209484250490600018105614048117055336074437503883703510511249361

22493198378815695858127594672917553146825187145285692314043598457757469857480393

45677748242309854210746050623711418779541821530464749835819412673987675591655439

46077062914571196477686542167660429831652624386837205668069376L

>>>

1. Python basic Object Type----number