What is object property in kivy?

OOP is a way of programming that is closer to how things are expressed in real life than other types of programming.

OOP is a paradigm of computer programming, which is a set of theories, standards, models and methods that allow organizing knowledge, and a well-defined means to visualize the problem domain and implement the solution to that problem in a programming language.

The OOP is based on the object model, where the main element is the object, which is a unit that contains all its characteristics and behaviors in itself, which makes it an independent whole, but that is interrelated with objects of its own. same class or other classes, as in the real world.

A way of programming that tries to find a solution to these problems is called object-oriented programming. New concepts are introduced which go beyond what is already known.

Among them are the following.

There are definitions of the properties of an object. The creation of an object from the definitions is instantiation.

There is a class. A set of attributes and data is provided by an entity to react to events.

They correspond to the real objects of the world that surround us, or the internal objects of the program. It is an example of a class.

The execution is triggered upon receipt of a message. It is what the object can do, from a behavioral point of view. A method can change the properties of the object or send a new message to another object in the system.

A communication directed to an object instructs it to execute one of its methods with certain parameters associated with the event that generated it.

The object knows how to respond and what operations can be performed with it, that's what it's defined by.

It's an event in the system where a user interacts with a machine or sends a message. The appropriate message is sent to the relevant object. The action that an object creates can be defined as an event.

The class has some characteristics.

A container of a data type associated with an object, which makes the data visible from outside the object, and whose value can be altered by the execution of some method is the default characteristics.

It is a variable that is private and can only be accessed by a method of the object, and that is used to indicate different scenarios for the object. It is not visible to the programmers who are handling the instance.

There are attributes, identity, relationships and methods.

The attributes and functions of an object are represented in a table or entity.

In python, OOP is expressed in a simple and easy to write way, but you must understand how OOP theory works and translate it into code in order to program.

The OOP theory tells us that all objects must belong to a class, since this is the basis for differentiating themselves from each other, having attributes and behaviors that distinguish them from other objects that belong to other classes, to create classes in python.

To create a class, we write the word class followed by the name of the class and a couple of parentheses. If the name of the class you have created has more than one word, you must use camel notation.

Since we have a class, we need to define its attributes and behaviors, and to do this we need to create a variable normally and a value that we want to give it:

Now that we have an attribute we can add a behavior that in python is known as methods, to define a method we do the same as we do with a function with the default word def and the name of said method but to differentiate a method from a function we do it by writing the parameter self inside its parentheses:

The word self refers to the objects that belong to the class and the word pass that we place inside the method indicates to the python interpreter that we have not yet defined any operation for that method, since, if we do not write the word pass when we still do not assign anything to the method when executing it will give us an error.

Now that we have explained this, we will finish defining the displacement method, and inside this we will only place a print that tells us "The car is moving on 4 wheels"

When we have our class ready, we can start creating objects that belong to that class, and then we do it.

We are specifying which class the object belongs to after the "=".

In order to show all the attributes and behaviors that an object has when executing an OOP program in python, we do the following.

To show what you are made of.

My object's attribute

To show the methods.

my method

In the next example, we will show the attribute and behavior of the class that we gave to our object on the screen.

If you followed this example, you would have a complete example like this.

When it is executed, it will show us the following:

You can see that we have created an object that belongs to a class and has unique attributes and behaviors that differentiate it from other objects.

In the OOP, we can add all the classes we want or need because our objects are vehicles and their different types. The bike class will have its own attributes and behaviors.

We now have two classes that will allow us to create more objects that have different attributes and behaviors.

The example will show us the following.

The OOP has three types of properties that make it possible to facilitate this way of programming, and in this lesson we will explain each of them.

The Greek pilo means many and morphism, which is what the word polymorphism means. Polymorphism is the ability of objects in different classes to use the same behavior but with different values.

In the previous example of classes, objects and methods, all vehicles have the ability to move, but they do not move in the same way since a motorcycle moves on two wheels and a car moves on four.

The method that gives the initial state to a class is known as the method that gives the initial state to a class and we will assign this method to it to see its function:

The parameters of the initial state of the puppy object are the ones we define in the color and breed method.

We will get the following when we execute this code.

The string method is one of the methods of the Python classes, and we can see what happens when we execute an output on the screen of what is instantiated in the object.

We ask python what the puppy has, and we get it:

Python tells us that we get an object of the Puppy type, it simply tells us that it is an instance in the Puppy class but I don't know what its properties are, that is, its color and its breed, so this is where the string method that we are going to define comes in:

We will get what is instantiated within that object thanks to the fact that we define the __str_ method.

This method is very similar to the string, but it is used for the python language to identify what is inside.

Having said this, it can be said that the differences that both have is that the string method is used so that a human can know what is inside the object while the repr() method is used so that the programmer knows what is inside. of the object, we're going to reuse the previous code, but this time we'll add an id attribute to it:

If we execute this code, we can see that the function returns a string telling us that there is an instance of the type puppy with the id number 1.

If you look closely, we get the format we gave by rewriting the repr() method, but anyone reading this will not know why it is represented in the form , only we programmers will know that it is an object because that is how the interpreter of Python refers to objects, even if other things are missing, such as the address in memory where it is located, but for this case we override the repr() method to show the type of object and the id assigned to said object.

Encapsulation is a way of giving exclusive use to the behaviors that a class possesses, that is, it protects those attributes and behaviors so that they are not used outside.

To make an attribute or behavior private in python, we have to put a couple of underscores before the name.

To start our encapsulation example, we are going to create a class that we will call “Example” and within it we will declare a method that we will call “public” that will contain a return that will only show a text string that will say “I am a public method in view of everything":

We will put a couple of underscores and a text string inside the method that is called private, but before its name.

We created an object for the example class and created two methods to print.

If we run the example, it will show us something similar.

OOP is a way of programming that is closer to how things are expressed in real life than other types of programming.

OOP is a paradigm of computer programming, which is a set of theories, standards, models and methods that allow organizing knowledge, and a well-defined means to visualize the problem domain and implement the solution to that problem in a programming language.

The OOP is based on the object model, where the main element is the object, which is a unit that contains all its characteristics and behaviors in itself, which makes it an independent whole, but that is interrelated with objects of its own. same class or other classes, as in the real world.

A way of programming that tries to find a solution is called object-oriented programming. New concepts are introduced which go beyond what is already known.

The following are included.

There are definitions of the properties of an object. The creation of an object from the definitions is called instantiation.

There is a class. A set of attributes and data is provided by the entity to react to events. They correspond to the real objects of the world that surround us, or the internal objects of the program. It is an example of a class.

The execution of an object is triggered by a message.

It is what the object can do from a behavioral point of view. A method can change the properties of the object or send a new message to another object in the system.

A communication directed to an object instructs it to execute one of its methods with certain parameters associated with the event that generated it

The object knows how to respond and what operations can be performed with it.

It's an event in the system where a user interacts with a machine or sends a message.

The appropriate message is sent to the object. The action that an object can generate is an event.

The class has some characteristics.

A container of a data type associated with an object, which makes the data visible from outside the object, and whose value can be altered by the execution of some method is the default characteristics.

It is a variable that is private and can only be accessed by a method of the object, and that is used to indicate different scenarios for the object. It is not visible to the programmers who are handling the instance.

There are attributes, identities, relationships and methods.

The attributes and functions of an object are represented in a table or entity.

In python, OOP is expressed in a simple and easy to write way, but you have to understand how OOP theory works and translate it into code in order to program.

The OOP theory tells us that all objects must belong to a class, since this is the basis for differentiating themselves from each other, having attributes and behaviors that distinguish them from other objects that belong to other classes.

To create a class, we write the word class followed by the name of the class and a few parentheses. If the name of the class you have created has more than one word, you must use camel notation.

Since we have a class, we need to define its attributes and behaviors, and to do this we need to create a variable normally and a value that we want to give it, and we need to leave the corresponding indentation.

Now that we have an attribute we can add a behavior that in python is known as methods, to define a method we do the same as we do with a function with the default word def and the name of said method but to differentiate a method from a function we do it by writing the parameter self inside its parentheses:

The word self refers to the objects that belong to the class and the word pass that we place inside the method indicates to the python interpreter that we have not yet defined any operation for that method, since, if we do not write the word pass when we still do not assign anything to the method when executing it will give us an error.

We will finish defining the displacement method and then place a print in it that says "The car is moving on 4 wheels."

When we have our class ready, we can start creating objects that belong to that class, and then we do it.

We are specifying which class the object belongs to after the "=".

In order to show all the attributes and behaviors that an object has when executing an OOP program in python, we do the following:

To show what you are made of.

My object's attribute

To show methods.

My method.

In the next example, we will show the attribute and behavior of the class that we gave to our object on the screen.

If you followed this example, you would have a complete example like this.

When it is executed, it will show us the following:

You can see that we have created an object that belongs to a class and has unique attributes and behaviors that differentiate it from other objects. In the OOP, we can add all the classes we want or need, because our objects are vehicles and their different types. The bike class will have its own attributes and behaviors.

We now have two classes that will allow us to create more objects that have different attributes and behaviors.

If we run the example, it will show us the following.

The OOP has three types of properties that make it possible to facilitate this way of programming, and in this lesson we will explain each of them.

The Greek pilo means many and morphism, which is what the word polymorphism means.

Polymorphism is the ability of objects of different classes to use the same behavior but with different values.

In the previous example of classes, objects and methods, all vehicles have the ability to move, but they do not move in the same way since a motorcycle moves on two wheels and a car moves on four.

The method that gives the initial state to a class is known as the method that gives the initial state to a class and we will assign this method to it to see its function:

The parameters of the initial state of the puppy object are the ones we define in the color and breed method.

When we execute this code, we will get the following:

The string method is one of the methods of the Python classes, and we can see what happens when we execute an output on the screen of what is instantiated in the object.

We ask python what the puppy has, and we get it.

Python tells us that we get an object of the Puppy type, it simply tells us that it is an instance in the Puppy class but I don't know what its properties are, that is, its color and its breed, so this is where the string method that we are going to define comes in:

We will get what is instantiated within that object thanks to the fact that we define the scrull method.

This method is very similar to the string and is used to identify what is inside the python language Having said this, it can be said that the differences that both have is that the string method is used so that a human can know what is inside the object while the repr() method is used so that the programmer knows what is inside. of the object, we're going to reuse the previous code, but this time we'll add an id attribute to it:

If we execute this code, we can see that the function returns a string telling us that there is an instance of the type puppy with the id number 1.

If you look closely, we get the format we gave by rewriting the repr() method, but anyone reading this will not know why it is represented in the form , only we programmers will know that it is an object because that is how the interpreter of Python refers to objects, even if other things are missing, such as the address in memory where it is located, but for this case we override the repr() method to show the type of object and the id assigned to said object.

Encapsulation is a way of giving exclusive use to the behaviors that a class has, that is, it protects them so that they are not used outside.

To make an attribute or behavior private in python, we have to put a couple of underscores before the name.

To start our encapsulation example, we are going to create a class that we will call “Example” and within it we will declare a method that we will call “public” that will contain a return that will only show a text string that will say “I am a public method in view of everything":

We will put a couple of underscores and a text string inside the method that is called private, but before its name.

We created an object for the example class and created two methods to print.

If we run the example, it will show us something similar.

Baha Blanca is from PyconAR.

Kivy is getting a little more serious with some people.

The audience level is Intermediate.

There is a description.

Kivy is a framework for building applications.

It wasn't difficult to start using this framework since I had never programmed for mobile phones in Python. The app required more advanced features and I had problems.

Summary.

The need to handle characteristics different from those of computer programming is generated by the development of mobile applications. Since the native language of the applications is Java, there are some challenges to be solved.

The type of file that describes the application components, calledwidgets, is required for programming using Kivy. These objects have their own characteristics that make programming for them easier.

The kv language is a typical file format of this framework.

There is a connection between python and kv files.

The object that represents the widgets can be accessed in a number of ways, the description of the organization in the kv files can be used.

Using a bunch of things.

You will get an error.

When Dos is instantiated in the MainWidget rule, the code is evaluated before the ObjectProperty language is bound to the label. The language property of Dos isn't defined at that time.

The simplest option is to simply share a StringProperty with the Spinner. You can give a default value to the property inside the dynamic class, unlike with the whole object.

Your code could look like this.

windows.py

You will get an error.

When Dos is instantiated in the MainWidget rule, the code is evaluated before the ObjectProperty language is bound to the label. The language property of Dos isn't defined at that time.

The simplest option is to simply share a StringProperty with the Spinner. You can give a default value to the property inside the dynamic class.

Your code could look like this.

There is a windows.py

Baha Blanca is a PyconAR 2016

Kivy is getting a little more serious with his friends.

The audience level is intermediate.

There is a description

Kivy is a framework that can be used to build applications. It wasn't difficult to start using this framework since I had never programmed for mobile phones before, but I started working with it a short time ago. I experienced problems when the app required more advanced features.

Summary

The need to handle characteristics different from those of computer programming is generated by the development of mobile applications. Since the native language of the applications is Java, there are some challenges to be solved.

The type of file that describes the application components, calledwidgets, is required for programming using Kivy. These objects have their own characteristics that make programming for them easier. The kv language is a file format that is typical of this framework.

There is a connection between python and kv files.

The object that represents the widgets can be accessed in a number of ways, the description of the organization in the kv files is one of them.

Using a bunch of things.