Pydantic Tutorial Code

main.py

import json
from datetime import UTC, datetime
from functools import partial
from typing import Annotated, Literal
from uuid import UUID, uuid4

from pydantic import (
    BaseModel,
    ConfigDict,
    EmailStr,
    Field,
    HttpUrl,
    SecretStr,
    ValidationError,
    ValidationInfo,
    computed_field,
    field_validator,
    model_validator,
)


class User(BaseModel):
    model_config = ConfigDict(
        populate_by_name=True,
        strict=True,
        extra="allow",
        frozen=True,
    )

    uid: UUID = Field(alias="id", default_factory=uuid4)
    username: Annotated[str, Field(min_length=3, max_length=20)]
    email: EmailStr
    password: SecretStr
    website: HttpUrl | None = None
    age: Annotated[int, Field(ge=13, le=130)]
    verified_at: datetime | None = None
    bio: str = ""
    is_active: bool = True

    first_name: str = ""
    last_name: str = ""
    follower_count: int = 0

    @field_validator("username")
    @classmethod
    def validate_username(cls, v: str) -> str:
        if not v.replace("_", "").isalnum():
            raise ValueError("Username must be alphanumeric (underscores allowed)")
        return v.lower()

    @field_validator("website", mode="before")
    @classmethod
    def add_https(cls, v: str | None) -> str | None:
        if v and not v.startswith(("http://", "https://")):
            return f"https://{v}"
        return v

    @computed_field
    @property
    def display_name(self) -> str:
        if self.first_name and self.last_name:
            return f"{self.first_name} {self.last_name}"
        return self.username

    @computed_field
    @property
    def is_influencer(self) -> bool:
        return self.follower_count >= 10000


class Comment(BaseModel):
    content: str
    author_email: EmailStr
    likes: int = 0


class BlogPost(BaseModel):
    title: Annotated[str, Field(min_length=1, max_length=200)]
    content: Annotated[str, Field(min_length=10)]
    author: User
    view_count: int = 0
    is_published: bool = False
    tags: list[str] = Field(default_factory=list)
    create_at: datetime = Field(default_factory=partial(datetime.now, tz=UTC))
    status: Literal["draft", "published", "archived"] = "draft"
    slug: Annotated[str, Field(pattern=r"^[a-z0-9-]+$")]

    comments: list[Comment] = Field(default_factory=list)


class UserRegistration(BaseModel):
    email: EmailStr
    password: str
    confirm_password: str

    @model_validator(mode="after")
    def passwords_match(self) -> "UserRegistration":
        if self.password != self.confirm_password:
            raise ValueError("Passwords do not match")
        return self


user_data = {
    "id": "3bc4bf25-1b73-44da-9078-f2bb310c7374",
    "username": "Corey_Schafer",
    "email": "CoreyMSchafer@gmail.com",
    "age": 39,
    "password": "secret123",
    "notes": "Kind've a Karen...",
}
user = User.model_validate_json(json.dumps(user_data))

user.email = "CoreyMSchafer2@gmail.com"

print(user.model_dump_json(indent=2))

snippets.txt

### New BlogPost
post = BlogPost(
    title="Getting Started with Python",
    content="Here's how to begin...",
    author_id="12345",
)


### Invalid User
try:
    user = User(
        uid=0,
        username="cs",
        email="CoreyMSchafer@gmail.com",
        age=12,
    )
except ValidationError as e:
    print(e)


### Valid User
user = User(
    username="coreyms",
    email="CoreyMSchafer@gmail.com",
    age=39,
    password="secret123",
)
print(user)


### Username Validation
@field_validator('username')
@classmethod
def validate_username(cls, v: str) -> str:
    if not v.replace('_', '').isalnum():
        raise ValueError('Username must be alphanumeric (underscores allowed)')
    return v.lower()


### URL Validation (no mode)
@field_validator('website')
@classmethod
def add_https(cls, v: str | None) -> str | None:
    if v and not v.startswith(('http://', 'https://')):
        return f'https://{v}'
    return v


### Model Validator
class UserRegistration(BaseModel):
    email: EmailStr
    password: str
    confirm_password: str
    
    @model_validator(mode='after')
    def passwords_match(self) -> 'UserRegistration':
        if self.password != self.confirm_password:
            raise ValueError('Passwords do not match')
        return self

try:
    registration = UserRegistration(
        email="CoreyMSchafer@gmail.com",
        password="secret123",
        confirm_password="secret456"
    )
except ValidationError as e:
    print(e)


### Computed Fields
first_name: str = ""
last_name: str = ""
follower_count: int = 0

@computed_field
@property
def display_name(self) -> str:
    if self.first_name and self.last_name:
        return f"{self.first_name} {self.last_name}"
    return self.username

@computed_field
@property
def is_influencer(self) -> bool:
    return self.follower_count >= 10000


### Comment Model
class Comment(BaseModel):
    content: str
    author_email: EmailStr
    likes: int = 0


### BlogPost Dictionary
post_data = {
    "title": "Understanding Pydantic Models",
    "content": "Pydantic makes data validation easy and intuitive...",
    "slug": "understanding-pydantic",
    "author": {
        "username": "coreyms",
        "email": "CoreyMSchafer@gmail.com",
        "age": 39,
        "password": "secret123",
    },
    "comments": [
        {
            "content": "I think I understand nested models now!",
            "author_email": "student@example.com",
            "likes": 25,
        },
        {
            "content": "Can you cover FastAPI next?",
            "author_email": "viewer@example.com",
            "likes": 15,
        },
    ],
}

post = BlogPost(**post_data)

print(post.model_dump_json(indent=2))


### User Dictionary
user_data = {
    "id": "3bc4bf25-1b73-44da-9078-f2bb310c7374",
    "username": "Corey_Schafer",
    "email": "CoreyMSchafer@gmail.com",
    "age": "39",
    "password": "secret123",
}
user = User.model_validate(user_data)

print(user.model_dump_json(indent=2))

import 'package:flutter/material.dart';

void main() {
runApp(const OrganelOyunuApp());
}

class OrganelOyunuApp extends StatelessWidget {
const OrganelOyunuApp({super.key});

@OverRide
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Organel Eşleştirme Oyunu',
theme: ThemeData(
colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
useMaterial3: true,
fontFamily: 'Roboto',
),
home: const OyunEkrani(),
);
}
}

// Organel verilerini tutacağımız basit bir model sınıfı
class Organel {
final String isim;
final String gorev;
final IconData ikon;
final Color renk;

Organel({
required this.isim,
required this.gorev,
required this.ikon,
required this.renk,
});
}

class OyunEkrani extends StatefulWidget {
const OyunEkrani({super.key});

@OverRide
State createState() => _OyunEkraniState();
}

class _OyunEkraniState extends State {
// Tüm organellerin ve görevlerinin listesi
final List tumOrganeller = [
Organel(isim: 'Mitokondri', gorev: 'Hücrenin enerji (ATP) santralidir.', ikon: Icons.bolt, renk: Colors.orange),
Organel(isim: 'Ribozom', gorev: 'Protein sentezinden sorumludur.', ikon: Icons.grain, renk: Colors.redAccent),
Organel(isim: 'Kloroplast', gorev: 'Fotosentez yaparak besin ve oksijen üretir.', ikon: Icons.eco, renk: Colors.green),
Organel(isim: 'Çekirdek', gorev: 'Hücrenin yönetim ve kalıtım merkezidir.', ikon: Icons.adjust, renk: Colors.deepPurple),
Organel(isim: 'Lizozom', gorev: 'Hücre içi sindirim yapar.', ikon: Icons.delete_sweep, renk: Colors.brown),
Organel(isim: 'Golgi Aygıtı', gorev: 'Salgı maddelerini üretir ve paketler.', ikon: Icons.waves, renk: Colors.blue),
Organel(isim: 'Koful', gorev: 'Atık maddeleri ve suyu depolar.', ikon: Icons.bubble_chart, renk: Colors.teal),
];

// Doğru eşleştirilen organellerin isimlerini tuttuğumuz liste
List eslesenler = [];

// Sürüklenecek ve hedeflenecek listeleri karıştırmak için
late List suruklenecekOrganeller;
late List hedefGorevler;

@OverRide
void initState() {
super.initState();
oyunuBaslat();
}

// Oyunu sıfırlayan ve listeleri karıştıran fonksiyon
void oyunuBaslat() {
setState(() {
eslesenler.clear();
// Listeleri kopyalayıp rastgele karıştırıyoruz
suruklenecekOrganeller = List.from(tumOrganeller)..shuffle();
hedefGorevler = List.from(tumOrganeller)..shuffle();
});
}

// Oyunun bitip bitmediğini kontrol eden fonksiyon
void kontrolEtOyunBittiMi() {
if (eslesenler.length == tumOrganeller.length) {
showDialog(
context: context,
barrierDismissible: false,
builder: (context) => AlertDialog(
title: const Text('Tebrikler! 🏆', textAlign: TextAlign.center),
content: const Text(
'Tüm hücre organellerini ve görevlerini başarıyla eşleştirdiniz. Artık tam bir biyoloji uzmanısınız!',
textAlign: TextAlign.center,
),
actionsAlignment: MainAxisAlignment.center,
actions: [
ElevatedButton.icon(
onPressed: () {
Navigator.of(context).pop();
oyunuBaslat();
},
icon: const Icon(Icons.refresh),
label: const Text('Yeniden Oyna'),
)
],
),
);
}
}

@OverRide
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.grey[100],
appBar: AppBar(
title: const Text('Hücre Organelleri Eşleştirme', style: TextStyle(fontWeight: FontWeight.bold)),
backgroundColor: Theme.of(context).colorScheme.primary,
foregroundColor: Colors.white,
actions: [
Center(
child: Padding(
padding: const EdgeInsets.symmetric(horizontal: 16.0),
child: Text(
'Skor: ${eslesenler.length} / ${tumOrganeller.length}',
style: const TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
),
),
)
],
),
body: Column(
children: [
// Üst Kısım: Sürüklenebilir Organel Çipleri
Container(
padding: const EdgeInsets.all(16.0),
decoration: BoxDecoration(
color: Colors.white,
boxShadow: [
BoxShadow(color: Colors.black.withOpacity(0.05), blurRadius: 10, offset: const Offset(0, 5))
],
),
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
const Text(
'Organelleri görevlerin üzerine sürükleyin:',
style: TextStyle(fontSize: 16, fontWeight: FontWeight.bold, color: Colors.black87),
textAlign: TextAlign.center,
),
const SizedBox(height: 12),
Wrap(
alignment: WrapAlignment.center,
spacing: 12.0,
runSpacing: 12.0,
children: suruklenecekOrganeller.map((organel) {
// Eğer organel eşleştirildiyse boş bir kutu göster
if (eslesenler.contains(organel.isim)) {
return Chip(
label: const Text('Eşleşti ✓'),
backgroundColor: Colors.grey[300],
labelStyle: TextStyle(color: Colors.grey[600]),
);
}

                // Eşleştirilmediyse sürüklenebilir Widget'ı göster
                return Draggable<String>(
                  data: organel.isim, // Taşınan veri (organel ismi)
                  feedback: Material( // Sürüklenirken görünen widget
                    color: Colors.transparent,
                    child: Chip(
                      elevation: 8,
                      backgroundColor: organel.renk,
                      label: Text(organel.isim, style: const TextStyle(color: Colors.white, fontSize: 18)),
                      avatar: Icon(organel.ikon, color: Colors.white),
                    ),
                  ),
                  childWhenDragging: Chip( // Sürüklenirken asıl yerinde görünen widget
                    backgroundColor: organel.renk.withOpacity(0.3),
                    label: Text(organel.isim, style: const TextStyle(color: Colors.transparent)),
                  ),
                  child: Chip( // Normal durumda görünen widget
                    elevation: 2,
                    backgroundColor: organel.renk,
                    label: Text(organel.isim, style: const TextStyle(color: Colors.white, fontWeight: FontWeight.bold)),
                    avatar: Icon(organel.ikon, color: Colors.white),
                  ),
                );
              }).toList(),
            ),
          ],
        ),
      ),
      
      // Alt Kısım: Görev Hedefleri Listesi
      Expanded(
        child: ListView.builder(
          padding: const EdgeInsets.all(16.0),
          itemCount: hedefGorevler.length,
          itemBuilder: (context, index) {
            final hedef = hedefGorevler[index];
            final eslestiMi = eslesenler.contains(hedef.isim);

            return DragTarget<String>(
              // Üzerine bırakılan veriyi kabul edip etmeme kuralı
              onWillAcceptWithDetails: (details) => !eslestiMi, 
              
              // Veri başarıyla bırakıldığında çalışır
              onAcceptWithDetails: (details) {
                if (details.data == hedef.isim) {
                  setState(() {
                    eslesenler.add(hedef.isim);
                  });
                  kontrolEtOyunBittiMi();
                } else {
                  // Hatalı eşleştirmede kullanıcıya bilgi ver
                  ScaffoldMessenger.of(context).showSnackBar(
                    SnackBar(
                      content: Text('Yanlış! ${details.data} bu görevi yapmaz.'),
                      backgroundColor: Colors.red,
                      duration: const Duration(seconds: 1),
                    ),
                  );
                }
              },
              builder: (context, candidateData, rejectedData) {
                // Hedef kartının görünümü
                return Card(
                  margin: const EdgeInsets.only(bottom: 12.0),
                  elevation: eslestiMi ? 1 : (candidateData.isNotEmpty ? 8 : 2),
                  color: eslestiMi 
                      ? hedef.renk.withOpacity(0.1) 
                      : (candidateData.isNotEmpty ? Colors.blue[50] : Colors.white),
                  shape: RoundedRectangleBorder(
                    borderRadius: BorderRadius.circular(12),
                    side: BorderSide(
                      color: eslestiMi ? hedef.renk : (candidateData.isNotEmpty ? Colors.blue : Colors.transparent),
                      width: 2,
                    ),
                  ),
                  child: ListTile(
                    contentPadding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
                    leading: Container(
                      width: 50,
                      height: 50,
                      decoration: BoxDecoration(
                        color: eslestiMi ? hedef.renk : Colors.grey[200],
                        shape: BoxShape.circle,
                      ),
                      child: Icon(
                        eslestiMi ? hedef.ikon : Icons.help_outline,
                        color: eslestiMi ? Colors.white : Colors.grey[500],
                      ),
                    ),
                    title: Text(
                      hedef.gorev,
                      style: TextStyle(
                        fontSize: 16,
                        fontWeight: eslestiMi ? FontWeight.bold : FontWeight.normal,
                        color: Colors.black87,
                      ),
                    ),
                    subtitle: eslestiMi
                        ? Text(hedef.isim, style: TextStyle(color: hedef.renk, fontWeight: FontWeight.bold, fontSize: 16))
                        : const Text('Buraya sürükleyin', style: TextStyle(fontStyle: FontStyle.italic)),
                  ),
                );
              },
            );
          },
        ),
      ),
    ],
  ),
  // Oyunu istediğiniz zaman yeniden başlatmak için buton
  floatingActionButton: FloatingActionButton(
    onPressed: oyunuBaslat,
    tooltip: 'Oyunu Sıfırla',
    child: const Icon(Icons.refresh),
  ),
);

}
}