Sanic 基础 - 2
1. 异常的处理
NotFound: 找不到合适的路由请求。ServerError: 服务器内部出现问题时调用。通常发生在用户代码出现错误的情况。
from sanic import Sanic
from sanic.exceptions import NotFound
from sanic.exceptions import ServerError
from sanic.response import text
app = Sanic(__name__)
@app.exception(NotFound)
def ignore_404s(request, exception):
# 捕获页面找不到异常 404
return text("Yep, I totally found the page: {}".format(request.url))
@app.route('/error')
def i_am_ready_to_die(request):
raise ServerError("抛出一个异常!!", status_code=500)
if __name__ == '__main__':
app.run()2. 中间件和监听器
中间件:
- 这里有两种不同类型的中间件：请求request和响应response。 都是使用
@app.middleware装饰器进行声明的，利用'request'或'response'字符串来表示其参数类型。
from sanic import Sanic
from sanic.exceptions import NotFound
from sanic.exceptions import ServerError
from sanic.response import text
app = Sanic(__name__)
@app.middleware('request')
async def print_on_request(request):
print("当服务器接收到请求时，我打印")
return text('I halted the request') # 修改响应内容
@app.middleware('response')
async def add_headers(request, response):
response.headers["Server"] = "Fake-Server"
@app.middleware('response')
async def add_headers(request, response):
print("当服务器返回响应时打印")
# 添加响应头
response.headers["x-xss-protection"] = "1; mode=block" # 将添加HTTP头以防止跨站点脚本（XSS）攻击。
# response.headers["Server"] = "Fake-Server"
return text('I halted the response') # 修改响应内容 就不会设置响应头了
@app.route('/')
async def index(request):
return text('OK')
if __name__ == '__main__':
app.run()
监听器:
from sanic import Sanic
from sanic.response import text
app = Sanic(__name__)
@app.listener('before_server_start')
async def setup_db(app, loop):
# app.db = await db_setup()
print("服务器开启时")
@app.listener('after_server_start')
async def notify_server_started(app, loop):
print("服务器成功启动时")
@app.listener('before_server_stop')
async def notify_server_stopping(app, loop):
print('服务器关闭之前')
@app.listener('after_server_stop')
async def close_db(app, loop):
print('服务器关闭之后')
await app.db.close()
async def notify_server_started_after_five_seconds():
await asyncio.sleep(5)
print('Server successfully started!')
app.add_task(notify_server_started_after_five_seconds())
@app.route('/')
async def index(request):
return text('OK')
if __name__ == '__main__':
app.run()3. 蓝图
3.1 实现并注册
蓝图
from sanic.response import json from sanic import Blueprint, Sanic # bp = Blueprint('my_blueprint') bp = Blueprint(__name__) # 名字随意 @bp.route('/') async def bp_root(request): return json({'my': 'blueprint'})注册
from sanic import Sanic from my_blueprint import bp app = Sanic(__name__) app.blueprint(bp) app.run(host='0.0.0.0', port=8000, debug=True)可全局注册中间件
@bp.middleware async def print_on_request(request): print("I am a spy") @bp.middleware('request') async def halt_request(request): return text('I halted the request') @bp.middleware('response') async def halt_response(request, response): return text('I halted the response')全局处理异常
@bp.exception(NotFound) def ignore_404s(request, exception): return text("Yep, I totally found the page: {}".format(request.url))静态文件
bp.static('/folder/to/serve', '/web/path')路由反响解析
from sanic.response import text, redirect from sanic import Blueprint, Sanic app = Sanic() blueprint_v1 = Blueprint('v1', url_prefix='/v1') app.blueprint(blueprint_v1) @blueprint_v1.route('/post/<arg>', name='post_handler') async def post_handler(request, arg): return text('Post {} in Blueprint V1'.format(arg)) print(app.url_for('v1.post_handler', arg=123)) # /v1/post/123监听
@bp.listener('before_server_start') async def setup_connection(app, loop): # global database # database = mysql.connect(host='127.0.0.1'...) print('开始') @bp.listener('after_server_stop') async def close_connection(app, loop): print('结束') # await database.close()
3.2 API版本控制
lueprints对于API版本控制非常有用，其中一个蓝图可能指向
/v1/<routes>，另一个指向/v2/<routes>。当蓝图被初始化时，它可以使用一个可选的
url_prefix参数，这个参数将被添加到蓝图上定义的所有路由上。此功能可用于实现API版本控制。
from sanic.response import text
from sanic import Blueprint
blueprint_v1 = Blueprint('v1', url_prefix='/v1')
blueprint_v2 = Blueprint('v2', url_prefix='/v2')
@blueprint_v1.route('/')
async def api_v1_root(request):
return text('版本一')
@blueprint_v2.route('/')
async def api_v2_root(request):
return text('版本二')- 注册
from sanic import Sanic
from blueprints import blueprint_v1, blueprint_v2
app = Sanic(__name__)
app.blueprint(blueprint_v1, url_prefix='/v1')
app.blueprint(blueprint_v2, url_prefix='/v2')
app.run(host='0.0.0.0', port=8000, debug=True)4. 配置
# 第一种方式
app = Sanic('myapp')
app.config.DB_NAME = 'appdb'
app.config.DB_USER = 'appuser'
# 第二种方式
db_settings = {
'DB_HOST': 'localhost',
'DB_NAME': 'appdb',
'DB_USER': 'appuser'
}
app.config.update(db_settings)配置加载方式
从环境变量加载
# 任何由SANIC_定义的变量都将应用于sanic配置。例如，设置SANIC_REQUEST_TIMEOUT自动加载应用程序。你可以使用load_cars将布尔值传递给Sanic构造函数来进行覆盖。 app = Sanic(load_vars=False)从对象加载
# 如果有很多配置参数并且它们有合理的默认值，将它们放置于模块是有帮助的。 import myapp.default_settings app = Sanic('myapp') app.config.from_object(myapp.default_settings)从文件加载
# 通常情况下，你想要从文件中加载配置参数。你可以从from_file(/path/to/config_file)来加载配置参数。然而，这需要程序知道配置文件的位置，所以你可以在环境变量中指定配置文件的路径，并让Sanic寻找配置文件并使用配置文件。 app = Sanic('myapp') app.config.from_envvar('MYAPP_SETTINGS') # 然后你可以在MYAPP_SETTINGS环境设置下运行你的应用程序： $ MYAPP_SETTINGS=/path/to/config_file python3 myapp.py INFO: Goin' Fast @ http://0.0.0.0:8000 # 配置文件是常规的Python文件，运行它们只是为了加载配置。这允许你使用任何正确的逻辑进行正确的配置。只要uppercase变量被添加到配置中，最常见的配置包括简单的键值对： # config_file DB_HOST = 'localhost' DB_NAME = 'appdb' DB_USER = 'appuser'
5. COOKIES
响应的cookies可以设置为字典值，同时也有以下参数可用：
expires(时间): cookie最后在客户端浏览器上存在时间。path(字符串): Cookie的URL子集。默认为/。comment(字符串): 注释（元数据）。domain(字符串): 指定cookie有效的域。显式指定的域必须始终以点开头。max-age(数字): cookie应该存在的秒数。secure(布尔值): 指定cookie是否只能通过HTTPS发送。httponly(布尔值): 指定cookie是否能被Javascript读取。
from sanic import Sanic
from sanic.response import text
app = Sanic()
@app.route("/get_cookie")
async def test(request):
test_cookie = request.cookies.get('test')
return text("Test cookie set to: {}".format(test_cookie))
@app.route("/set_cookie")
async def test(request):
response = text("There's a cookie up in this response")
response.cookies['id'] = 'It worked!'
# response.cookies['test']['domain'] = '.gotta-go-fast.com'
# response.cookies['test']['httponly'] = True
return response
@app.route("/del_cookie")
async def test(request):
response = text("删除cookies")
# 此cookie将被设置为0秒后过期
del response.cookies['kill_me']
# 这个cookie将在5秒内自动销毁
response.cookies['short_life'] = 'Glad to be here'
response.cookies['short_life']['max-age'] = 5
del response.cookies['favorite_color']
# This cookie will remain unchanged
response.cookies['favorite_color'] = 'blue'
response.cookies['favorite_color'] = 'pink'
del response.cookies['favorite_color']
return response
if __name__ == '__main__':
app.run()
6.装饰器添加
from functools import wraps
from sanic import Sanic
from sanic.response import json
app = Sanic()
def auth():
def decorator(f):
@wraps(f)
async def decorated_function(request, *args, **kwargs):
# 判断是否通过 认证
is_authorized = True
if is_authorized:
# 通过认证
response = await f(request, *args, **kwargs)
return response
else:
# 未通过认证
return json({'status': 'not_authorized'}, 403)
return decorated_function
return decorator
@app.route("/")
@auth()
async def test(request):
return json({"status": 'authorized'})
if __name__ == '__main__':
app.run()7. CBV 试图写法
from functools import wraps
from sanic.response import text, json, redirect
from sanic.views import HTTPMethodView, CompositionView
from sanic import Sanic
app = Sanic(__name__)
def auth():
def decorator(f):
@wraps(f)
async def decorated_function(request, *args, **kwargs):
# 判断是否通过 认证
is_authorized = True
print("认证装饰器")
if is_authorized:
# 通过认证
response = await f(request, *args, **kwargs)
return response
else:
# 未通过认证
return json({'status': 'not_authorized'}, 403)
return decorated_function
return decorator
# @app.route('/')
async def index(request):
url = app.url_for('Users', id=10) # 反向解析
print(url) # /user/10
return redirect(url) # 302
# 使用组成视图 处理错误请求
view = CompositionView()
view.add(['GET'], index)
view.add(['POST', 'PUT'], lambda request: text('我没有 post / put 方法'))
app.add_route(view, '/')
class Users(HTTPMethodView):
decorators = [auth(), ] # 加装饰器
# 可以不使用异步
async def get(self, request, id):
print(id)
return text('{}---OK'.format(id))
async def post(self, request,id):
return text("{}".format(request.form))
...
app.add_route(Users.as_view(), '/user/<id>')
if __name__ == '__main__':
app.run()
8.自定义协议
from sanic import Sanic
from sanic.response import text
from sanic.server import HttpProtocol
app = Sanic()
# 自定义 http 协议
class CustomHttpProtocol(HttpProtocol):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
def write_response(self, response):
if isinstance(response, str):
response = text(response)
self.transport.write(
response.output(self.request.version)
)
self.transport.close()
@app.route('/')
async def string(request):
return 'string'
@app.route('/1')
async def response(request):
return text('response')
app.run(protocol=CustomHttpProtocol) # 指定协议
9.SSL 证书
import ssl
ctx = ssl.create_default_context(purpose=ssl.Purpose.CLIENT_AUTH)
ctx.load_cert_chain("/path/to/cert", keyfile="/path/to/keyfile")
app.run(host="0.0.0.0", port=8443, ssl=ctx)
# 你还可以将证书和密钥的位置做为自检进行传递。
ssl = {'cert': "/path/to/cert", 'key': "/path/to/keyfile"}
app.run(host="0.0.0.0", port=5000, ssl=ssl)
10.命令行启动
- 需要指定 server.py 文件为启动文件
python -m sanic server.app --host=0.0.0.0 --port=80 --workers=4