from flask import Flask, request, g, redirect # g对象的特性: # 1.当前请求内你设置就可以取,必须先设置,然后取,当前请求可以无限次 # 2.如果不是当前请求,其他请求,也取不到 app = Flask(__name__) @app.before_request def dou(): if request.path == '/index': request.name = 'sb' g.name = 'sb' def set_g(): g.name = '老子最帅' # @app.route('/') # def index(): # set_g() # return redirect('/index') # @app.route('/index') def login(): print(g.name) return '2b' if __name__ == '__main__': app.run(port=8000)
信号:
from flask import Flask, signals app = Flask(__name__) # 第一步,编写一个函数 def func(*args, **kwargs): print('触发信号', args, kwargs) # 第二部:注册信号 signals.request_started.connect(func) # 请求来之前执行这个 # 第三部:触发信号(内置信号,不需要手动触发,框架自动触发) @app.route('/') def index(): return 'index' if __name__ == '__main__': app.run()
""" request_started = _signals.signal('request-started') # 请求到来前执行 request_finished = _signals.signal('request-finished') # 请求结束后执行 before_render_template = _signals.signal('before-render-template') # 模板渲染前执行 template_rendered = _signals.signal('template-rendered') # 模板渲染后执行 got_request_exception = _signals.signal('got-request-exception') # 请求执行出现异常时执行 request_tearing_down = _signals.signal('request-tearing-down') # 请求执行完毕后自动执行(无论成功与否) appcontext_tearing_down = _signals.signal('appcontext-tearing-down')# 应用上下文执行完毕后自动执行(无论成功与否) appcontext_pushed = _signals.signal('appcontext-pushed') # 应用上下文push时执行 appcontext_popped = _signals.signal('appcontext-popped') # 应用上下文pop时执行 message_flashed = _signals.signal('message-flashed') # 调用flask在其中添加数据时,自动触发 """
自定义信号
from flask import Flask, current_app, flash, render_template from flask.signals import _signals app = Flask(import_name=__name__) # 1.自定义信号 xxxxx = _signals.signal('xxxxx') # 2.定义函数 def func(*args, **kwargs): print('信号来了', args, kwargs) # 3.绑定函数 xxxxx.connect(func) @app.route("/x") def index(): # 触发信号 xxxxx.send('123123', k1='v1') # 自定义就在这里,需要什么时候执行(此时就是试图执行后运行信号) return 'Index' if __name__ == '__main__': app.run()
local
""" 多个线程同时修改同一个数据,会造成数据混乱, 方法一:加线程锁 方法二:复制多份变量给每个线程用,为每个线程开辟一块空间进行数据存储 """ # from threading import Thread # import time # # cxw = -1 # # # def task(arg): # global cxw # cxw = arg # time.sleep(2) # print(cxw) # # # for i in range(10): # t = Thread(target=task, args=(i,)) # t.start() # 结果为9,9,9为什么全部是9,当第一进程启动进去,等待2秒,因为异步其他进程也同时启动最终,cxm全局结果赋值为最后的9 # from threading import Thread # from threading import local # import time # from threading import get_ident # # # 特殊的对象 # cxw = local() # # # def task(arg): # # 对象.val = 1/2/3/4/5 # # cxw['线程id']['value']=arg # cxw.value = arg # time.sleep(2) # # cxw['线程id']['value'] # print(cxw.value) # # # for i in range(10): # t = Thread(target=task, args=(i,)) # t.start() # 把数据存储到一个对象中,每个线程分配一个变量进行独立操作 # 函数的方式 from threading import get_ident, Thread import time storage = {} def set(k, v): ident = get_ident() if ident in storage: storage[ident][k] = v else: # cxw['线程id']['value']=arg # storage[1][val]=arg # storage={1:{val:agr}} storage[ident] = {k: v} def get(k): ident = get_ident() # 1 # storage = {1: {val: agr}} return storage[ident][k] def task(arg): set('val', arg) time.sleep(1) v = get('val') print(v) for i in range(10): t = Thread(target=task, args=(i,)) t.start()
请求上下文
""" 多个线程同时修改同一个数据,会造成数据混乱, 方法一:加线程锁 方法二:复制多份变量给每个线程用,为每个线程开辟一块空间进行数据存储 """ # from threading import Thread # import time # # cxw = -1 # # # def task(arg): # global cxw # cxw = arg # time.sleep(2) # print(cxw) # # # for i in range(10): # t = Thread(target=task, args=(i,)) # t.start() # 结果为9,9,9为什么全部是9,当第一进程启动进去,等待2秒,因为异步其他进程也同时启动最终,cxm全局结果赋值为最后的9 # from threading import Thread # from threading import local # import time # from threading import get_ident # # # 特殊的对象 # cxw = local() # # # def task(arg): # # 对象.val = 1/2/3/4/5 # # cxw['线程id']['value']=arg # cxw.value = arg # time.sleep(2) # # cxw['线程id']['value'] # print(cxw.value) # # # for i in range(10): # t = Thread(target=task, args=(i,)) # t.start() # 把数据存储到一个对象中,每个线程分配一个变量进行独立操作 # 函数的方式 from threading import get_ident, Thread import time storage = {} def set(k, v): ident = get_ident() if ident in storage: storage[ident][k] = v else: # cxw['线程id']['value']=arg # storage[1][val]=arg # storage={1:{val:agr}} storage[ident] = {k: v} def get(k): ident = get_ident() # 1 # storage = {1: {val: agr}} return storage[ident][k] def task(arg): set('val', arg) time.sleep(1) v = get('val') print(v) for i in range(10): t = Thread(target=task, args=(i,)) t.start()
flask-session
from flask import Flask, session from flask_session import RedisSessionInterface import redis app = Flask(__name__) app.secret_key = "ajksda" conn = redis.Redis(host='127.0.0.1', port=6379) # use_signer是否对key签名 app.session_interface = RedisSessionInterface(conn, key_prefix='jason', use_signer=True, permanent=False) @app.route('/') def hello_world(): session['sb'] = 'jason' return 'Hello World!' @app.route("/index") def index(): print(session['sb']) return "ok" if __name__ == '__main__': app.run()
session第二种方法
from flask import Flask, session # 推荐 import redis from flask_session import Session app = Flask(__name__) app.config['SESSION_TYPE'] = 'redis' app.config['SESSION_REDIS'] = redis.Redis(host='127.0.0.1', port='6379') app.config['SESSION_KEY_PREFIX'] = "jason" Session(app) @app.route('/') def hello_world(): session['sb'] = 'jason' return 'Hello World!' @app.route("/index") def index(): print(session['sb']) return "ok" if __name__ == '__main__': app.run()
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