The first knowledge of Python (2) __python object

Python Object

Everything in Python is an object, so-called object: I am an object, I play the computer is the object, sitting chair is the object, the home of the puppy is an object ...

We describe an object by describing attributes (characteristics) and behavior. For example, the puppy in the home, its color, size, age, weight, etc. is its properties or characteristics. It will bark, will wag its tail, and so on is its behavior.

We include two aspects when describing a real object (object):

What it can do (behavior)

What it is (attributes or characteristics).

In Python, the characteristics of an object are also known as attributes (attribute). The behavior it has is also called the method.

Conclusion: Object = attribute + method

Object Three features:

1. Identity: Unique identity flag, which is the memory address of the object, which can be used to obtain the type of the built-in function ID ()
2. Type: integer, float, character, etc. you can use the built-in function type () to view the type of the Python object, and type () returns an object instead of a simple string. For example:

>>> B = 1>>> type (b)'int'> >>> type (int) ' type '>>>> type'type' >

The type of B is int, and the type of int is ' type ', type or type.

3. Value: The data item represented by the object

Object Properties

attribute : A property that is used to describe the characteristics of a particular object and is static. For example: Yao Ming is more than 2.6 meters tall, small white hair is brown, two lang God has an eye on the forehead;

Standard type

• Number (divided into sub-types, three of which are integer)
• Integral type
• Boolean type
• Long integer type
• Floating point Type
• Plural type
• String
• List
• Meta-group
• Dictionary

Data type	Storage model	Update model	Access model
Digital	Scalar Atomic Type	Cannot be changed	Direct access
String	Scalar Atomic Type	Cannot be changed	Sequential access
List	Container container	Can be changed	Sequential access
Meta-group	Container container	Cannot be changed	Sequential access
Dictionary	Container container	Can be changed	Map Access

Other types:

• Type
• Null object (None)
• File
• Set/fixed Set
• Functions/Methods
• Module
• Class

Internal type (tentative initial understanding)

• Code: Reference: Code objects in Python
• Frame:
• Tracking Records
• Slices: A Slice object is created when the tiling syntax is extended using Python. Extended slice syntax allows for different index slicing operations, including stepping slices, multidimensional slices, and omitting slices. The multidimensional slice syntax is sequence[start1:end1,start2:end2], or use the ellipsis, Sequence[...,start1:end1]. The slice object can also be generated by the built-in function slice (). Step slices allow stepping slices with the third slice element, whose syntax is sequence[start index: End index: Step value]
• Omitted
• Xrange

Built-in functions

built-in Functions
ABS ()	Divmod ()	Input ()	Open ()	Staticmethod ()
All ()	Enumerate ()	Int ()	Ord ()	STR ()
Any ()	Eval ()	Isinstance ()	POW ()	SUM ()
Basestring ()	ExecFile ()	Issubclass ()	Print ()	Super ()
Bin ()	File ()	ITER ()	Property ()	Tuple ()
BOOL ()	Filter ()	Len ()	Range ()	Type ()
ByteArray ()	Float ()	List ()	Raw_input ()	UNICHR ()
Callable ()	Format ()	Locals ()	Reduce ()	Unicode ()
Chr ()	Frozenset ()	Long ()	Reload ()	VARs ()
Classmethod ()	GetAttr ()	Map ()	Repr ()	Xrange ()
CMP ()	Globals ()	Max ()	Reversed ()	Zip ()
Compile ()	Hasattr ()	Memoryview ()	Round ()	__import__ ()
Complex ()	Hash ()	Min ()	Set ()	Apply ()
Delattr ()	Help ()	Next ()	SetAttr ()	Buffer ()
Dict ()	Hex ()	Object ()	Slice ()	Coerce ()
Dir ()	ID ()	Oct ()	Sorted ()	Intern ()

Reference official website: built-in Functions

Standard type operators and built-in functions

Operator/function	Description	Result
String
‘‘	String representation	St
CMP (OBJ1, OBJ2)	Compares objects	Inch
Repr (obj)	String representation	St
STR (obj)	String representation	St
Type (obj)	Determines object type	Typ
Value Comparisons
<	Less than	Boo
>	Greater than	Boo
<=	Less than or equal to	Boo
>=	Greater than or equal to	Boo
==	Equal to	Boo
!=	Not equal to	Boo
<>	Not equal to	Boo
Object Comparisons
Is	The same as	Boo
is not	Not the same as	Boo
Boolean operators
Not	Logical negation	Boo
and	Logical conjunction	Boo
Or	Logical disjunction	Boo

Factory functions

Although they look a bit like functions, they are essentially classes. When you call them, you actually generate an instance of the type.

Int (), long (), float (), complex (), str (), Unicode (), basestring (), list (), tuple (), type ()

Dict (), BOOL (), set (), Frozenset (), Object (), Classmethod (), Staticmethod (), super (), property (), file ()

The first knowledge of Python (2) __python object