General Syntaxe pythonquestion : from typed language to untyped one-CodePudding

I'am new to python language. And my question is certainly a naive one and concerne python syntaxe.

I am a the step where I must go from theory to practice.

here is a class (a typescript one) I want to translate to python language.

class Category {
    id: number;
    type: 'shop'|'blog';
    name: string;
    slug: string;
    path: string;
    image: string|null;
    items: number;
    customFields: CustomFields;
    parents?: Category[]|null;
    children?: Category[]|null;
}

as python is untyped language I've got doubts about how to translate :

the optional property : '?'
the associated class : customFields: CustomFields;
the arrays of associated class (that are self associated) and that are nullable : children?: Category[]|null;

I've always worked with typed language until now and it's destabilisising my habits to just write nothing.

would that look like this (it's a model for django.db migration):

>from django.db import models

    >>class Category(models.Model):
    >>>    id = models.AutoField(primary_key=True)
    >>>   type: 'shop'|'blog'
    >>>    name = models.CharField(max_length=100)
    >>>    slug = models.CharField(max_length=100)
    >>>    path = models.CharField(max_length=250)

and then ... ?

could you provide also some tuto, doc, example where you learn python in pratice ? thanks to all of you !

CodePudding user response：

When you define a function in Python you can enforce static typing but its not necessary. In case you need to have a static typing enforced you can do something like this.

//for functions
def addition(a: int, b: int) -> int:
    return a   b
addition(4,10)

//For Variables or attributes
name: str = 'test'
age: int = 10
rating: float = 1.11
is_exist: bool = True

There are more things found in python documentation related to typing in case you can refer documentation.

CodePudding user response：

If you must enforce typing in your Python code, take a look at isinstance.
For optional Class attributes in Python, you can use keyword arguments as shown in this answer.

CodePudding user response：

it's best to learn the language by following the documentation for it, there are enough examples in the documentation. https://docs.python.org/3/

If you want to learn Django, there are quite a lot of tutorials. But first of all, look here. https://docs.djangoproject.com/en/3.2/

As for your example with the Category Class The id is determined automatically and it is not necessary to explicitly specify it in the model, see more https://docs.djangoproject.com/en/3.2/topics/db/models/