get the attributes of a class in python ?

Description

https://www.geeksforgeeks.org › how-to-get-a-list-of-class-attributes-in-python

https://www.geeksforgeeks.org › how-to-get-a-list-of-class-attributes-in-python
How to Get a List of Class Attributes in Python?
To get the list of all the attributes, methods along with some inherited magic methods of a class, we use a built-in called dir (). Example: Python3 class Number : one = ‘first’ two = ‘second’ three = ‘third’ def __init__ (self, attr): self.attr = attr def show (self): print(self.one, self.two, self.three, self.attr) n = Number (2) n.show ()

https://stackoverflow.com › questions › 9058305 › getting-attributes-of-a-class

https://stackoverflow.com › questions › 9058305 › getting-attributes-of-a-class
python – Getting attributes of a class – Stack Overflow
3. If you want to get an attribute, there is a very simple answer, which should be obvious: getattr. class MyClass (object): a = ’12’ b = ’34’ def myfunc (self): return self.a >>> getattr (MyClass, ‘a’) ’12’ >>> getattr (MyClass, ‘myfunc’) .

https://www.askpython.com › python › oops › class-instance-attributes

https://www.askpython.com › python › oops › class-instance-attributes
Attributes of a Class in Python – AskPython
You can access the attributes and methods of a class by using the dot operator (.). For example, if you want to access the attribute x of the class myClass, you would use the expression myClass.x. If you want to call the method myMethod of the class myClass, you would use the expression myClass.myMethod ().

https://www.pythontutorial.net › python-oop › python-class-attributes

https://www.pythontutorial.net › python-oop › python-class-attributes
Understanding Python Class Attributes By Practical Examples
When you access an attribute via an instance of the class, Python searches for the attribute in the instance attribute list. If the instance attribute list doesn’t have that attribute, Python continues looking up the attribute in the class attribute list.

https://www.geeksforgeeks.org › accessing-attributes-methods-python

https://www.geeksforgeeks.org › accessing-attributes-methods-python
Accessing Attributes and Methods in Python – GeeksforGeeks
Attributes of a class can also be accessed using the following built-in methods and functions : getattr () – This function is used to access the attribute of object. hasattr () – This function is used to check if an attribute exist or not. setattr () – This function is used to set an attribute.

https://docs.python.org › 3 › tutorial › classes.html

https://docs.python.org › 3 › tutorial › classes.html
9. Classes — Python 3.11.2 documentation
Attribute references use the standard syntax used for all attribute references in Python: obj.name. Valid attribute names are all the names that were in the class’s namespace when the class object was created. So, if the class definition looked like this: class MyClass: A simple example class i = 12345 def f(self): return ‘hello world’

https://stackoverflow.com › questions › 66499217 › python-how-to-get-attributes-and-their-type-from-a-dataclass

https://stackoverflow.com › questions › 66499217 › python-how-to-get-attributes-and-their-type-from-a-dataclass
Python: How to get attributes and their type from a dataclass?
For classes in general, you can access the __annotations__: >>> class Foo: … bar: int … baz: str … >>> Foo.__annotations__ {‘bar’: , ‘baz’: } This returns a dict mapping attribute name to annotation. However, dataclasses have use dataclass.field objects to encapsulate a lot of this information.

https://stackoverflow.com › questions › 2675028 › list-attributes-of-an-object

https://stackoverflow.com › questions › 2675028 › list-attributes-of-an-object
python – List attributes of an object – Stack Overflow
You can use dir (your_object) to get the attributes and getattr (your_object, your_object_attr) to get the values usage : for att in dir (your_object): print (att, getattr (your_object,att)) This is particularly useful if your object have no __dict__.

https://www.codespeedy.com › get-a-list-of-class-attributes-in-python

https://www.codespeedy.com › get-a-list-of-class-attributes-in-python
Get a List of Class Attributes in Python – CodeSpeedy
Using the dir () method to find all the class attributes. It returns a list of the attributes and methods of the passed object/class. On being called upon class objects, it returns a list of names of all the valid attributes and base attributes too. Syntax: dir (object) , where object is optional.

https://www.austadiums.com › sport › comp › nbl › tickets

www.learningaboutelectronics.com › Articles › How-to-display-all-attributes-of-a-class-or-instance-of-a-class-in-Python.php
How to Display All Attributes of a Class or an Instance of a Class in …
And then run the __dict__ method, we get the following output. Now you can see this attribute of the class displayed with the __dict__ method. So the __dict__ method is a very useful method in Python to display all attributes of an instance of a class or other data type such as a class itself.

Cet article est une ébauche concernant l’informatique.
Vous pouvez partager vos connaissances en l’améliorant (comment ?) selon les recommandations des projets correspondants.
Pour les articles homonymes, voir Propriété (homonymie).
En programmation orientée objet ou en Resource Description Framework, une propriété est un élément de description d’un objet. Un type de classe regroupe, entre autres, l’ensemble des propriétés communes à un type d’objet.
Une propriété, dans certains langages de programmation orientés objet, est une sorte de membre de classe. Il se traduit par un champ du point de vue de l’interface d’une classe, mais auquel sont adjoints une ou plusieurs méthodes, dites accesseurs et mutateurs, vouées à lire (get / accesseur) et (set / mutateur) la valeur du champ de l’instance.
Le champ de la propriété peut selon le langage se traduire par un attribut, éventuellement homonyme des accesseurs (getter ou setter).
Utilisation des propriétés[|]
L’usage courant des propriétés est de pouvoir rajouter des instructions appliquées systématiquement au moment de la modification ou de la lecture de toute instance d’une classe sans pour autant l’interface de cette classe.
Les propriétés sont également utilisées pour contrôler l’accès au champ, en rendant celui-ci private pour forcer l’usage aux accesseurs, dans lesquels des contrôles de cohérence peuvent être insérés.
Cette faculté permissive est cependant source de risques, notamment du fait qu’elle permet de les valeurs d’attribut(s) lors d’opération vouée normalement à leur lecture.
Exemples de syntaxe[|]
C et dérivés[|]
Propriétés en C#[|]
class Pen {
private int m_Color; // private field

public int Color { // public property
get
{
return m_Color;
}
set
{
m_Color = value;
}
}
}
// accessing:
Pen pen = new Pen();
// …
pen.Color = ~pen.Color; // bitwise complement …

// another silly example:
pen.Color += 1; // a lot clearer than pen.set_Color(pen.get_Color() + 1)!
Les dernières versions de C# autorisent de plus les auto-implemented properties, pour lesquelles le champ sous-jacent à la propriété est généré par le compilateur à la compilation. Ceci implique que la propriété ait un ‘setter’, éventuellement privé.
class Shape {

public Int32 Height { get; set; }
public Int32 Width { get; private set; }

}
Propriétés en C++[|]
C++ n’a pas de propriétés de classe, mais il existe plusieurs manières d’imiter les propriétés dans une certaine limite. Voici deux exemples :
#include

template class property {
T value;
public:
T & operator = (const T &i) {
::std::cout << i << ::std::endl;
return value = i;
}
// This template class member function template serves the purpose to make
// typing more strict. Assignment to this is only possible with exact identical
// types.
template T2 & operator = (const T2 &i) {
::std::cout << T2: << i << ::std::endl;
T2 &guard = value;
throw guard; // Never reached.
}
operator T const & () const {
return value;
}
};

struct Foo {
// Properties using unnamed classes.
class {
int value;
public:
int & operator = (const int &i) { return value = i; }
operator int () const { return value; }
} alpha;

class {
float value;
public:
float & operator = (const float &f) { return value = f; }
operator float () const { return value; }
} bravo;
};

struct Bar {
// Using the property-template.
property alpha;
property bravo;
};

int main () {
Foo foo;
foo.alpha = 5;
foo.bravo = 5.132f;

Bar bar;
bar.alpha = true;
bar.bravo = true; // This line will yield a compile time error
// due to the guard template member function.
::std::cout << foo.alpha << ,
<< foo.bravo << ,
<< bar.alpha << ,
<< bar.bravo
<< ::std::endl;
return 0;
}
Propriétés en C++, Microsoft & C++Builder-specific[|]
Un exemple tiré de la MSDN documentation page []:
// declspec_property.cpp
struct S
{
int i;
void putprop(int j)
{
i = j;
}

int getprop()
{
return i;
}

__declspec(property(get = getprop, put = putprop)) int the_prop;
};

int main()
{
S s;
s.the_prop = 5;
return s.the_prop;
}
Propriétés en Objective-C 2.0[|]

@interface Pen : NSObject {
NSColor *color;
}
@property(copy) NSColor *color; // color values always copied.
@end

@implementation Pen
@synthesize color; // synthesize accessor methods.
@end

// Example Usage
Pen *pen = [[Pen alloc] init];
pen.color = [NSColor blackColor];
float red = pen.color.redComponent;
[pen.color drawSwatchInRect:NSMakeRect(0, 0, 100, 100)];
Notez que le moderne Objective-C runtime peut convertir les variables d'instance en propriétés, d'où la déclaration explicite des variables d'instance qui n'est pas nécessaire, mais toujours possible.
Nouveaux langages[|]
Propriétés en langage D[|]
class Pen
{
private int m_color; // private field

// public get property
public int color () {
return m_color;
}

// public set property
public int color (int value) {
return m_color = value;
}
}
auto pen = new Pen;
pen.color = ~pen.color; // bitwise complement

// the set property can also be used in expressions, just like regular assignment
int theColor = (pen.color = 0xFF0000);
Dans D version 2, chaque accesseur de propriété doit être marqué avec @property:
class Pen
{
private int m_color; // private field

// public get property
@property public int color () {
return m_color;
}

// public set property
@property public int color (int value) {
return m_color = value;
}
}
Propriétés en Delphi/Free Pascal[|]
type TPen = class
private
m_Color: Integer;
function Get_Color: Integer;
procedure Set_Color(RHS: Integer);
public
property Color: Integer read Get_Color write Set_Color;
end;

function TPen.Get_Color: Integer;
begin
Result := m_Color
end;

procedure TPen.Set_Color(RHS: Integer);
begin
m_Color := RHS
end;
// accessing:
var pen: TPen;
// …
pen.Color := not pen.Color;

(*
Delphi also supports a 'direct field' syntax –

property Color: Integer read m_Color write Set_Color;

or

property Color: Integer read Get_Color write m_Color;

where the compiler generates the exact same code as for reading and writing
a field. This offers the efficiency of a field, with the safety of a property.
(You can't get a pointer to the property, and you can always replace the member
access with a method call.)
*)
Propriétés en F#[|]
type Pen() = class
let mutable _color = 0

member this.Color
with get() = _color
and set value = _color <- value
end
let pen = new Pen()
pen.Color _color = $value;
}
}

function __get($property) {
if ($property == ‘Color’) {
return $this->_color;
}
}
}
$p = new Pen();
$p->Color = ~$p->Color; // bitwise complement
echo $p->Color;
Propriétés en Python[|]
Les propriétés ne fonctionnent correctement que pour les nouveaux types de classe qui sont uniquement disponibles en Python 2.2 ou plus récents. Python 2.6 ajoute une nouvelle syntaxe pour définir les propriétés.
class Pen(object):
def __init__(self):
self._color = 0 # private variable

@property
def color(self):
return self._color

@color.setter
def color(self, color):
self._color = color
pen = Pen()
# accessing:
pen.color = ~pen.color # bitwise complement …
Propriétés en Ruby[|]
class Pen
def initialize
@color = 0
end
# there is actually a shortcut for these: attr_accessor :color will
# synthetise both methods automatically, it was expanded for
# compatibility with properties actually worth writing out
def color
@color
end
def color = value
@color = value
end
end

pen = Pen.new
pen.color = ~pen.color
Langages Visual Basic[|]
Propriétés en Visual Basic (.NET to 2010)[|]
Public Class Pen

Private m_Color As Integer ‘ Private field

Public Property Color As Integer ‘ Public property
Get
Return m_Color
End Get
Set(ByVal Value As Integer)
m_Color = Value
End Set
End Property

End Class
‘ accessing:
Dim pen As New Pen()
‘ …
pen.Color = Not pen.Color
Propriétés en Visual Basic 6[|]
‘ in a class named clsPen
Private m_Color As Long

Public Property Get Color() As Long
Color = m_Color
End Property

Public Property Let Color(ByVal RHS As Long)
m_Color = RHS
End Property
‘ accessing:
Dim pen As New clsPen
‘ …
pen.Color = Not pen.Color
Voir aussi[|]
Interface (informatique)
Notes et références[|]
↑ http://www.ecma-international.org/ecma-262/6.0/ []
[]
v · m
Unified Modeling Language
Organismes
ISO Object Management Group Partenaires UML
Personnalités
Grady Booch Ivar Jacobson James Rumbaugh
Concepts
Orientation objet
POO Méthode d’analyse et de conception d’applications orientées objet Encapsulation Héritage Polymorphisme
Structure
Acteur Artéfact Attribut Classe Composant Interface Objet Package Propriété
Comportement
Activité Événement Message Méthode État Cas d’utilisation
Relation
Agrégation Association Composition Dépendance Généralisation Héritage
Autres
Cardinalité Profil Stéréotype
Diagrammes
Structure
Classes Composants Structure composite Déploiement Objets Paquetages Profils
Comportement
Activité État Cas d’utilisation
Interaction
Communication Séquence Global d’interaction Temps
Articles liés
Unified Process Comparaison des outils UML Systems Modeling Language Colorisation d’UML XMI
Portail de la programmation informatiquelesoutrali bot