# Flask RESTPlus

***

**1. Simple API with GET and POST endpoints:**

```python
from flask_restplus import Api, Resource, fields

# Create a RESTful API
api = Api()

# Create a model for the POST endpoint
post_model = api.model('Post', {'title': fields.String, 'content': fields.String})

# Define the POST endpoint
@api.route('/posts')
class Posts(Resource):
    @api.expect(post_model)
    def post(self):
        # Logic to create a new post
        return {'success': True}

# Define the GET endpoint
@api.route('/posts')
class Posts(Resource):
    def get(self):
        # Logic to get all posts
        return {'posts': []}
```

**2. API with authentication and paginated results:**

```python
from flask import request
from flask_restplus import Api, Resource, fields, reqparse

# Create a RESTful API
api = Api()

# Create a model for user authentication
user_model = api.model('User', {'username': fields.String, 'password': fields.String})

# Create a parser for user authentication
auth_parser = reqparse.RequestParser()
auth_parser.add_argument('username', type=str, required=True)
auth_parser.add_argument('password', type=str, required=True)

# Define the login endpoint
@api.route('/login')
class Login(Resource):
    @api.expect(auth_parser)
    def post(self):
        # Logic to authenticate user
        return {'access_token': 'my-token'}

# Create a parser for pagination
pagination_parser = reqparse.RequestParser()
pagination_parser.add_argument('page', type=int, default=1)
pagination_parser.add_argument('per_page', type=int, default=10)

# Define the posts endpoint with pagination
@api.route('/posts')
class Posts(Resource):
    @api.expect(pagination_parser)
    def get(self):
        # Logic to get paginated posts
        return {'posts': [], 'total_pages': 1}
```

**3. API with file uploads:**

```python
from flask import request, send_file
from flask_restplus import Api, Resource, fields

# Create a RESTful API
api = Api()

# Create a model for file upload
file_model = api.model('File', {'name': fields.String, 'content': fields.Raw})

# Define the file upload endpoint
@api.route('/files')
class Files(Resource):
    @api.expect(file_model)
    def post(self):
        # Logic to save file
        return {'success': True}

    def get(self, file_id):
        # Logic to get file by ID
        return send_file('file.txt')
```

**4. API with rate limiting:**

```python
from flask_limiter import Limiter
from flask_limiter.util import get_remote_address
from flask_restplus import Api, Resource, fields

# Create a RESTful API
api = Api()

# Initialize the rate limiter
limiter = Limiter(app, key_func=get_remote_address)

# Create a model for rate limit policy
rate_limit_model = api.model('RateLimit', {'limit': fields.Integer, 'remaining': fields.Integer})

# Define the rate limit endpoint
@api.route('/rate-limit')
class RateLimit(Resource):
    @limiter.limit('10 per minute')
    def get(self):
        # Logic to check rate limit
        return {'rate_limit': {'limit': 10, 'remaining': 9}}
```

**5. API with error handling:**

```python
from flask_restplus import Api, Resource, fields

# Create a RESTful API
api = Api()

# Define custom error handler
@api.errorhandler
def default_error_handler(error):
    return {'message': str(error)}, error.code

# Define the posts endpoint
@api.route('/posts')
class Posts(Resource):
    def get(self):
        raise Exception('Internal server error')
```

**6. API with documentation (Swagger UI):**

```python
from flask_restplus import Api, Resource, fields, swag_from

# Create a RESTful API
api = Api(doc='/api', title='My API')

# Create a model for the GET endpoint
get_model = api.model('Get', {'id': fields.Integer, 'name': fields.String})

# Define the GET endpoint with documentation
@api.route('/posts/<int:post_id>')
@swag_from('get_model.yml')
class Post(Resource):
    def get(self, post_id):
        # Logic to get post by ID
        return {'post': {'id': post_id, 'name': 'Post Name'}}
```

**7. API with versioning:**

```python
from flask import request
from flask_restplus import Api, Resource, fields

# Create a RESTful API with versioning
api = Api(version='1.0', title='My API')

# Define the posts endpoint
@api.route('/posts')
class Posts(Resource):
    def get(self):
        # Logic to get posts
        return {'posts': []}

# Define the posts endpoint for version 2
@api.route('/posts', version='2.0')
class Posts(Resource):
    def get(self):
        # Logic to get posts with additional data
        return {'posts': [], 'additional_data': []}
```

**8. API with CORS:**

```python
from flask import request, current_app
from flask_cors import CORS
from flask_restplus import Api, Resource, fields

# Create a RESTful API
api = Api()

# Enable CORS
CORS(current_app)

# Define the posts endpoint
@api.route('/posts')
class Posts(Resource):
    def get(self):
        # Logic to get posts
        return {'posts': []}
```

**9. API with jwt authentication:**

```python
from flask_jwt_extended import (
    JWTManager, jwt_required, create_access_token,
    get_jwt_identity
)
from flask_restplus import Api, Resource, fields

# Create a RESTful API
api = Api()

# Initialize JWT manager
jwt = JWTManager()

# Create a model for JWT authentication
jwt_model = api.model('JWT', {'access_token': fields.String})

# Define the login endpoint
@api.route('/login')
class Login(Resource):
    @api.expect(jwt_model)
    def post(self):
        # Logic to authenticate user
        access_token = create_access_token(identity='username')
        return {'access_token': access_token}

# Define the posts endpoint with JWT authentication
@api.route('/posts')
@jwt_required
class Posts(Resource):
    def get(self):
        # Logic to get posts
        current_user = get_jwt_identity()
        return {'posts': []}
```

**10. API with custom scopes:**

```python
from flask_jwt_extended import (
    JWTManager, jwt_required, create_access_token,
    get_jwt_identity, get_jwt_claims
)
from flask_restplus import Api, Resource, fields

# Create a RESTful API
api = Api()

# Initialize JWT manager
jwt = JWTManager()

# Define custom scopes
scopes = {'read:posts', 'write:posts'}

# Create a model for JWT authentication
jwt_model = api.model('JWT', {'access_token': fields.String})

# Define the login endpoint
@api.route('/login')
class Login(Resource):
    @api.expect(jwt_model)
    def post(self):
        # Logic to authenticate user
        access_token = create_access_token(identity='username', scopes=['read:posts'])
        return {'access_token': access_token}

# Define the posts endpoint with JWT authentication and custom scopes
@api.route('/posts')
@jwt_required
def get_posts():
    # Logic to get posts based on user's scopes
    current_user = get_jwt_identity()
    scopes = get_jwt_claims()
    if 'read:posts' in scopes:
        return {'posts': []}
    else:
        return {'error': 'Permission denied'}, 403
```

**11. API with automatic documentation:**

```python
from flask_restplus import Api, Resource, fields

# Create a RESTful API
api = Api(doc='/api')

# Create a model for the GET endpoint
get_model = api.model('Get', {'id': fields.Integer, 'name': fields.String})

# Define the GET endpoint with automatic documentation
@api.route('/posts/<int:post_id>')
class Post(Resource):
    @api.doc(responses={200: 'Success'})
    def get(self, post_id):
        # Logic to get post by ID
        return {'post': {'id': post_id, 'name': 'Post Name'}}
```

**12. API with namespace:**