python高级之Flask框架
目录：
- Flask基本使用
- Flask配置文件
- Flask路由系统
- Flask模版
- Flask请求与响应
- Flask之Session
- Flask之蓝图
- Flask之message
- 中间件
- Flask插件
一、Flask基本使用
1、flask简介
lask是一个基于Python开发并且依赖jinja2模板和Werkzeug WSGI服务的一个微型框架，对于Werkzeug本质是Socket服务端，其用于接收http请求并对请求进行预处理，然后触发Flask框架，开发人员基于Flask框架提供的功能对请求进行相应的处理，并返回给用户，如果要返回给用户复杂的内容时，需要借助jinja2模板来实现对模板的处理，即：将模板和数据进行渲染，将渲染后的字符串返回给用户浏览器。
“微”(micro) 并不表示你需要把整个 Web 应用塞进单个 Python 文件（虽然确实可以 ），也不意味着 Flask 在功能上有所欠缺。微框架中的“微”意味着 Flask 旨在保持核心简单而易于扩展。Flask 不会替你做出太多决策——比如使用何种数据库。而那些 Flask 所选择的——比如使用何种模板引擎——则很容易替换。除此之外的一切都由可由你掌握。如此，Flask 可以与您珠联璧合。
默认情况下，Flask 不包含数据库抽象层、表单验证，或是其它任何已有多种库可以胜任的功能。然而，Flask 支持用扩展来给应用添加这些功能，如同是 Flask 本身实现的一样。众多的扩展提供了数据库集成、表单验证、上传处理、各种各样的开放认证技术等功能。Flask 也许是“微小”的，但它已准备好在需求繁杂的生产环境中投入使用。
2、flask安装
pip3 install flask
3、flask之werkaeug
from werkzeug.wrappers import Request, Response
@Request.application
def hello(request):
return Response('Hello World!')
if __name__ == '__main__':
from werkzeug.serving import run_simple
run_simple('localhost', 4000, hello)
1 from werkzeug.wrappers import Request, Response
2
3 @Request.application
4 def hello(request):
5 return Response('Hello World!')
6
7 if __name__ == '__main__':
8 from werkzeug.serving import run_simple
9 run_simple('localhost', 4000, hello)
4、flask基本使用
二、Flask配置文件
flask中的配置文件是一个flask.config.Config对象（继承字典）,默认配置为：
{
'DEBUG': get_debug_flag(default=False), 是否开启Debug模式
'TESTING': False, 是否开启测试模式
'PROPAGATE_EXCEPTIONS': None,
'PRESERVE_CONTEXT_ON_EXCEPTION': None,
'SECRET_KEY': None,
'PERMANENT_SESSION_LIFETIME': timedelta(days=31),
'USE_X_SENDFILE': False,
'LOGGER_NAME': None,
'LOGGER_HANDLER_POLICY': 'always',
'SERVER_NAME': None,
'APPLICATION_ROOT': None,
'SESSION_COOKIE_NAME': 'session',
'SESSION_COOKIE_DOMAIN': None,
'SESSION_COOKIE_PATH': None,
'SESSION_COOKIE_HTTPONLY': True,
'SESSION_COOKIE_SECURE': False,
'SESSION_REFRESH_EACH_REQUEST': True,
'MAX_CONTENT_LENGTH': None,
'SEND_FILE_MAX_AGE_DEFAULT': timedelta(hours=12),
'TRAP_BAD_REQUEST_ERRORS': False,
'TRAP_HTTP_EXCEPTIONS': False,
'EXPLAIN_TEMPLATE_LOADING': False,
'PREFERRED_URL_SCHEME': 'http',
'JSON_AS_ASCII': True,
'JSON_SORT_KEYS': True,
'JSONIFY_PRETTYPRINT_REGULAR': True,
'JSONIFY_MIMETYPE': 'application/json',
'TEMPLATES_AUTO_RELOAD': None,
}
1 {
2 'DEBUG': get_debug_flag(default=False), 是否开启Debug模式
3 'TESTING': False, 是否开启测试模式
4 'PROPAGATE_EXCEPTIONS': None,
5 'PRESERVE_CONTEXT_ON_EXCEPTION': None,
6 'SECRET_KEY': None,
7 'PERMANENT_SESSION_LIFETIME': timedelta(days=31),
8 'USE_X_SENDFILE': False,
9 'LOGGER_NAME': None,
10 'LOGGER_HANDLER_POLICY': 'always',
11 'SERVER_NAME': None,
12 'APPLICATION_ROOT': None,
13 'SESSION_COOKIE_NAME': 'session',
14 'SESSION_COOKIE_DOMAIN': None,
15 'SESSION_COOKIE_PATH': None,
16 'SESSION_COOKIE_HTTPONLY': True,
17 'SESSION_COOKIE_SECURE': False,
18 'SESSION_REFRESH_EACH_REQUEST': True,
19 'MAX_CONTENT_LENGTH': None,
20 'SEND_FILE_MAX_AGE_DEFAULT': timedelta(hours=12),
21 'TRAP_BAD_REQUEST_ERRORS': False,
22 'TRAP_HTTP_EXCEPTIONS': False,
23 'EXPLAIN_TEMPLATE_LOADING': False,
24 'PREFERRED_URL_SCHEME': 'http',
25 'JSON_AS_ASCII': True,
26 'JSON_SORT_KEYS': True,
27 'JSONIFY_PRETTYPRINT_REGULAR': True,
28 'JSONIFY_MIMETYPE': 'application/json',
29 'TEMPLATES_AUTO_RELOAD': None,
30 }
1、调用方式
方式一：
app.config['DEBUG'] = True
PS： 由于Config对象本质上是字典，所以还可以使用app.config.update(...)
方式二：
app.config.from_pyfile("python文件名称")
如：
settings.py
DEBUG = True
app.config.from_pyfile("settings.py")
app.config.from_envvar("环境变量名称")
环境变量的值为python文件名称名称，内部调用from_pyfile方法
app.config.from_json("json文件名称")
JSON文件名称，必须是json格式，因为内部会执行json.loads
app.config.from_mapping({'DEBUG':True})
字典格式
app.config.from_object("python类或类的路径")
app.config.from_object('pro_flask.settings.TestingConfig')
settings.py
class Config(object):
DEBUG = False
TESTING = False
DATABASE_URI = 'sqlite://:memory:'
class ProductionConfig(Config):
DATABASE_URI = 'mysql://user@localhost/foo'
class DevelopmentConfig(Config):
DEBUG = True
class TestingConfig(Config):
TESTING = True
1 方式一：
2 app.config['DEBUG'] = True
3
4 PS： 由于Config对象本质上是字典，所以还可以使用app.config.update(...)
5
6 方式二：
7 app.config.from_pyfile("python文件名称")
8 如：
9 settings.py
10 DEBUG = True
11
12 app.config.from_pyfile("settings.py")
13
14 app.config.from_envvar("环境变量名称")
15 环境变量的值为python文件名称名称，内部调用from_pyfile方法
16
17
18 app.config.from_json("json文件名称")
19 JSON文件名称，必须是json格式，因为内部会执行json.loads
20
21 app.config.from_mapping({'DEBUG':True})
22 字典格式
23
24 app.config.from_object("python类或类的路径")
25
26 app.config.from_object('pro_flask.settings.TestingConfig')
27
28 settings.py
29
30 class Config(object):
31 DEBUG = False
32 TESTING = False
33 DATABASE_URI = 'sqlite://:memory:'
34
35 class ProductionConfig(Config):
36 DATABASE_URI = 'mysql://user@localhost/foo'
37
38 class DevelopmentConfig(Config):
39 DEBUG = True
40
41 class TestingConfig(Config):
42 TESTING = True
PS: 从sys.path中已经存在路径开始写
PS: settings.py文件默认路径要放在程序root_path目录，如果instance_relative_config为True，则就是instance_path目录
三、Flask路由系统
1、基本路由系统
- @app.route('/user/<username>')
- @app.route('/post/<int:post_id>')
- @app.route('/post/<float:post_id>')
- @app.route('/post/<path:path>')
- @app.route('/login', methods=['GET', 'POST'])
常用路由系统有以上五种，所有的路由系统都是基于一下对应关系来处理：
DEFAULT_CONVERTERS = {
'default': UnicodeConverter, 'string': UnicodeConverter, 'any': AnyConverter, 'path': PathConverter, 'int': IntegerConverter, 'float': FloatConverter, 'uuid': UUIDConverter,}def auth(func):
def inner(*args, **kwargs):
print('before')
result = func(*args, **kwargs)
print('after')
return result
return inner
@app.route('/index.html',methods=['GET','POST'],endpoint='index')
@auth
def index():
return 'Index'
或
def index():
return "Index"
self.add_url_rule(rule='/index.html', endpoint="index", view_func=index, methods=["GET","POST"])
or
app.add_url_rule(rule='/index.html', endpoint="index", view_func=index, methods=["GET","POST"])
app.view_functions['index'] = index
或
def auth(func):
def inner(*args, **kwargs):
print('before')
result = func(*args, **kwargs)
print('after')
return result
return inner
class IndexView(views.View):
methods = ['GET']
decorators = [auth, ]
def dispatch_request(self):
print('Index')
return 'Index!'
app.add_url_rule('/index', view_func=IndexView.as_view(name='index')) # name=endpoint
或
class IndexView(views.MethodView):
methods = ['GET']
decorators = [auth, ]
def get(self):
return 'Index.GET'
def post(self):
return 'Index.POST'
app.add_url_rule('/index', view_func=IndexView.as_view(name='index')) # name=endpoint
@app.route和app.add_url_rule参数：
rule, URL规则
view_func, 视图函数名称
defaults=None, 默认值,当URL中无参数，函数需要参数时，使用defaults={'k':'v'}为函数提供参数
endpoint=None, 名称，用于反向生成URL，即： url_for('名称')
methods=None, 允许的请求方式，如：["GET","POST"]
strict_slashes=None, 对URL最后的 / 符号是否严格要求，
如：
@app.route('/index',strict_slashes=False)，
访问 http://www.xx.com/index/ 或 http://www.xx.com/index均可
@app.route('/index',strict_slashes=True)
仅访问 http://www.xx.com/index
redirect_to=None, 重定向到指定地址
如：
@app.route('/index/<int:nid>', redirect_to='/home/<nid>')
或
def func(adapter, nid):
return "/home/888"
@app.route('/index/<int:nid>', redirect_to=func)
subdomain=None, 子域名访问
from flask import Flask, views, url_for
app = Flask(import_name=__name__)
app.config['SERVER_NAME'] = 'wupeiqi.com:5000'
@app.route("/", subdomain="admin")
def static_index():
"""Flask supports static subdomains
This is available at static.your-domain.tld"""
return "static.your-domain.tld"
@app.route("/dynamic", subdomain="<username>")
def username_index(username):
"""Dynamic subdomains are also supported
Try going to user1.your-domain.tld/dynamic"""
return username + ".your-domain.tld"
if __name__ == '__main__':
app.run()
1 def auth(func):
2 def inner(*args, **kwargs):
3 print('before')
4 result = func(*args, **kwargs)
5 print('after')
6 return result
7
8 return inner
9
10 @app.route('/index.html',methods=['GET','POST'],endpoint='index')
11 @auth
12 def index():
13 return 'Index'
14
15 或
16
17 def index():
18 return "Index"
19
20 self.add_url_rule(rule='/index.html', endpoint="index", view_func=index, methods=["GET","POST"])
21 or
22 app.add_url_rule(rule='/index.html', endpoint="index", view_func=index, methods=["GET","POST"])
23 app.view_functions['index'] = index
24
25
26 或
27 def auth(func):
28 def inner(*args, **kwargs):
29 print('before')
30 result = func(*args, **kwargs)
31 print('after')
32 return result
33
34 return inner
35
36 class IndexView(views.View):
37 methods = ['GET']
38 decorators = [auth, ]
39
40 def dispatch_request(self):
41 print('Index')
42 return 'Index!'
43
44 app.add_url_rule('/index', view_func=IndexView.as_view(name='index')) # name=endpoint
45
46
47
48 或
49
50
51 class IndexView(views.MethodView):
52 methods = ['GET']
53 decorators = [auth, ]
54
55 def get(self):
56 return 'Index.GET'
57
58 def post(self):
59 return 'Index.POST'
60
61
62 app.add_url_rule('/index', view_func=IndexView.as_view(name='index')) # name=endpoint
63
64
65
66
67 @app.route和app.add_url_rule参数：
68 rule, URL规则
69 view_func, 视图函数名称
70 defaults=None, 默认值,当URL中无参数，函数需要参数时，使用defaults={'k':'v'}为函数提供参数
71 endpoint=None, 名称，用于反向生成URL，即： url_for('名称')
72 methods=None, 允许的请求方式，如：["GET","POST"]
73
74
75 strict_slashes=None, 对URL最后的 / 符号是否严格要求，
76 如：
77 @app.route('/index',strict_slashes=False)，
78 访问 http://www.xx.com/index/ 或 http://www.xx.com/index均可
79 @app.route('/index',strict_slashes=True)
80 仅访问 http://www.xx.com/index
81 redirect_to=None, 重定向到指定地址
82 如：
83 @app.route('/index/<int:nid>', redirect_to='/home/<nid>')
84 或
85 def func(adapter, nid):
86 return "/home/888"
87 @app.route('/index/<int:nid>', redirect_to=func)
88 subdomain=None, 子域名访问
89 from flask import Flask, views, url_for
90
91 app = Flask(import_name=__name__)
92 app.config['SERVER_NAME'] = 'wupeiqi.com:5000'
93
94
95 @app.route("/", subdomain="admin")
96 def static_index():
97 """Flask supports static subdomains
98 This is available at static.your-domain.tld"""
99 return "static.your-domain.tld"
100
101
102 @app.route("/dynamic", subdomain="<username>")
103 def username_index(username):
104 """Dynamic subdomains are also supported
105 Try going to user1.your-domain.tld/dynamic"""
106 return username + ".your-domain.tld"
107
108
109 if __name__ == '__main__':
110 app.run()
111
3、自定义路由匹配（正则匹配）
from flask import Flask, views, url_for
from werkzeug.routing import BaseConverter
app = Flask(import_name=__name__)
class RegexConverter(BaseConverter):
"""
自定义URL匹配正则表达式
"""
def __init__(self, map, regex):
super(RegexConverter, self).__init__(map)
self.regex = regex
def to_python(self, value):
"""
路由匹配时，匹配成功后传递给视图函数中参数的值
:param value:
:return:
"""
return int(value)
def to_url(self, value):
"""
使用url_for反向生成URL时，传递的参数经过该方法处理，返回的值用于生成URL中的参数
:param value:
:return:
"""
val = super(RegexConverter, self).to_url(value)
return val
# 添加到flask中
app.url_map.converters['regex'] = RegexConverter
@app.route('/index/<regex("\d+"):nid>')
def index(nid):
print(url_for('index', nid='888'))
return 'Index'
if __name__ == '__main__':
app.run()
1 from flask import Flask, views, url_for
2 from werkzeug.routing import BaseConverter
3
4 app = Flask(import_name=__name__)
5
6
7 class RegexConverter(BaseConverter):
8 """
9 自定义URL匹配正则表达式
10 """
11 def __init__(self, map, regex):
12 super(RegexConverter, self).__init__(map)
13 self.regex = regex
14
15 def to_python(self, value):
16 """
17 路由匹配时，匹配成功后传递给视图函数中参数的值
18 :param value:
19 :return:
20 """
21 return int(value)
22
23 def to_url(self, value):
24 """
25 使用url_for反向生成URL时，传递的参数经过该方法处理，返回的值用于生成URL中的参数
26 :param value:
27 :return:
28 """
29 val = super(RegexConverter, self).to_url(value)
30 return val
31
32 # 添加到flask中
33 app.url_map.converters['regex'] = RegexConverter
34
35
36 @app.route('/index/<regex("\d+"):nid>')
37 def index(nid):
38 print(url_for('index', nid='888'))
39 return 'Index'
40
41
42 if __name__ == '__main__':
43 app.run()
四、Flask模版
1、模板的使用
Flask使用的是Jinja2模板，所以其语法和Django无差别
2、自定义模板方法
Flask中自定义模板方法的方式和Bottle相似，创建一个函数并通过参数的形式传入render_template，如：
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
</head>
<body>
<h1>自定义函数</h1>
{{ww()|safe}}
</body>
</html>
复制代码
html
1 <!DOCTYPE html>
2 <html>
3 <head lang="en">
4 <meta charset="UTF-8">
5 <title></title>
6 </head>
7 <body>
8 <h1>自定义函数</h1>
9 {{ww()|safe}}
10
11 </body>
12 </html>
13 复制代码
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from flask import Flask,render_template
app = Flask(__name__)
def wangshuyang():
return '<h1>Wupeiqi</h1>'
@app.route('/login', methods=['GET', 'POST'])
def login():
return render_template('login.html', ww=wangshuyang)
app.run()
五、Flask请求与响应
from flask import Flask
from flask import request
from flask import render_template
from flask import redirect
from flask import make_response
app = Flask(__name__)
@app.route('/login.html', methods=['GET', "POST"])
def login():
# 请求相关信息
# request.method
# request.args
# request.form
# request.values
# request.cookies
# request.headers
# request.path
# request.full_path
# request.script_root
# request.url
# request.base_url
# request.url_root
# request.host_url
# request.host
# request.files
# obj = request.files['the_file_name']
# obj.save('/var/www/uploads/' + secure_filename(f.filename))
# 响应相关信息
# return "字符串"
# return render_template('html模板路径',**{})
# return redirect('/index.html')
# response = make_response(render_template('index.html'))
# response是flask.wrappers.Response类型
# response.delete_cookie('key')
# response.set_cookie('key', 'value')
# response.headers['X-Something'] = 'A value'
# return response
return "内容"
if __name__ == '__main__':
app.run()
1 from flask import Flask
2 from flask import request
3 from flask import render_template
4 from flask import redirect
5 from flask import make_response
6
7 app = Flask(__name__)
8
9
10 @app.route('/login.html', methods=['GET', "POST"])
11 def login():
12
13 # 请求相关信息
14 # request.method
15 # request.args
16 # request.form
17 # request.values
18 # request.cookies
19 # request.headers
20 # request.path
21 # request.full_path
22 # request.script_root
23 # request.url
24 # request.base_url
25 # request.url_root
26 # request.host_url
27 # request.host
28 # request.files
29 # obj = request.files['the_file_name']
30 # obj.save('/var/www/uploads/' + secure_filename(f.filename))
31
32 # 响应相关信息
33 # return "字符串"
34 # return render_template('html模板路径',**{})
35 # return redirect('/index.html')
36
37 # response = make_response(render_template('index.html'))
38 # response是flask.wrappers.Response类型
39 # response.delete_cookie('key')
40 # response.set_cookie('key', 'value')
41 # response.headers['X-Something'] = 'A value'
42 # return response
43
44
45 return "内容"
46
47 if __name__ == '__main__':
48 app.run()
六、Flask之Session
除请求对象之外，还有一个 session 对象。它允许你在不同请求间存储特定用户的信息。它是在 Cookies 的基础上实现的，并且对 Cookies 进行密钥签名要使用会话，你需要设置一个密钥。
-
设置：session['username'] ＝ 'xxx'
- 删除：session.pop('username', None)
1、基本使用
from flask import Flask, session, redirect, url_for, escape, request
app = Flask(__name__)
@app.route('/')
def index():
if 'username' in session:
return 'Logged in as %s' % escape(session['username'])
return 'You are not logged in'
@app.route('/login', methods=['GET', 'POST'])
def login():
if request.method == 'POST':
session['username'] = request.form['username']
return redirect(url_for('index'))
return '''
<form action="" method="post">
<p><input type=text name=username>
<p><input type=submit value=Login>
</form>
'''
@app.route('/logout')
def logout():
# remove the username from the session if it's there
session.pop('username', None)
return redirect(url_for('index'))
# set the secret key. keep this really secret:
app.secret_key = 'A0Zr98j/3yX R~XHH!jmN]LWX/,?RT'
1 from flask import Flask, session, redirect, url_for, escape, request
2
3 app = Flask(__name__)
4
5 @app.route('/')
6 def index():
7 if 'username' in session:
8 return 'Logged in as %s' % escape(session['username'])
9 return 'You are not logged in'
10
11 @app.route('/login', methods=['GET', 'POST'])
12 def login():
13 if request.method == 'POST':
14 session['username'] = request.form['username']
15 return redirect(url_for('index'))
16 return '''
17 <form action="" method="post">
18 <p><input type=text name=username>
19 <p><input type=submit value=Login>
20 </form>
21 '''
22
23 @app.route('/logout')
24 def logout():
25 # remove the username from the session if it's there
26 session.pop('username', None)
27 return redirect(url_for('index'))
28
29 # set the secret key. keep this really secret:
30 app.secret_key = 'A0Zr98j/3yX R~XHH!jmN]LWX/,?RT'
2、自定义session（Flask-Session插件）
pip3 install Flask-Session
run.py
from flask import Flask
from flask import session
from pro_flask.utils.session import MySessionInterface
app = Flask(__name__)
app.secret_key = 'A0Zr98j/3yX R~XHH!jmN]LWX/,?RT'
app.session_interface = MySessionInterface()
@app.route('/login.html', methods=['GET', "POST"])
def login():
print(session)
session['user1'] = 'alex'
session['user2'] = 'alex'
del session['user2']
return "内容"
if __name__ == '__main__':
app.run()
session.py
#!/usr/bin/env python
# -*- coding:utf-8 -*-
import uuid
import json
from flask.sessions import SessionInterface
from flask.sessions import SessionMixin
from itsdangerous import Signer, BadSignature, want_bytes
class MySession(dict, SessionMixin):
def __init__(self, initial=None, sid=None):
self.sid = sid
self.initial = initial
super(MySession, self).__init__(initial or ())
def __setitem__(self, key, value):
super(MySession, self).__setitem__(key, value)
def __getitem__(self, item):
return super(MySession, self).__getitem__(item)
def __delitem__(self, key):
super(MySession, self).__delitem__(key)
class MySessionInterface(SessionInterface):
session_class = MySession
container = {}
def __init__(self):
import redis
self.redis = redis.Redis()
def _generate_sid(self):
return str(uuid.uuid4())
def _get_signer(self, app):
if not app.secret_key:
return None
return Signer(app.secret_key, salt='flask-session',
key_derivation='hmac')
def open_session(self, app, request):
"""
程序刚启动时执行，需要返回一个session对象
"""
sid = request.cookies.get(app.session_cookie_name)
if not sid:
sid = self._generate_sid()
return self.session_class(sid=sid)
signer = self._get_signer(app)
try:
sid_as_bytes = signer.unsign(sid)
sid = sid_as_bytes.decode()
except BadSignature:
sid = self._generate_sid()
return self.session_class(sid=sid)
# session保存在redis中
# val = self.redis.get(sid)
# session保存在内存中
val = self.container.get(sid)
if val is not None:
try:
data = json.loads(val)
return self.session_class(data, sid=sid)
except:
return self.session_class(sid=sid)
return self.session_class(sid=sid)
def save_session(self, app, session, response):
"""
程序结束前执行，可以保存session中所有的值
如：
保存到resit
写入到用户cookie
"""
domain = self.get_cookie_domain(app)
path = self.get_cookie_path(app)
httponly = self.get_cookie_httponly(app)
secure = self.get_cookie_secure(app)
expires = self.get_expiration_time(app, session)
val = json.dumps(dict(session))
# session保存在redis中
# self.redis.setex(name=session.sid, value=val, time=app.permanent_session_lifetime)
# session保存在内存中
self.container.setdefault(session.sid, val)
session_id = self._get_signer(app).sign(want_bytes(session.sid))
response.set_cookie(app.session_cookie_name, session_id,
expires=expires, httponly=httponly,
domain=domain, path=path, secure=secure)
1 pip3 install Flask-Session
2
3 run.py
4 from flask import Flask
5 from flask import session
6 from pro_flask.utils.session import MySessionInterface
7 app = Flask(__name__)
8
9 app.secret_key = 'A0Zr98j/3yX R~XHH!jmN]LWX/,?RT'
10 app.session_interface = MySessionInterface()
11
12 @app.route('/login.html', methods=['GET', "POST"])
13 def login():
14 print(session)
15 session['user1'] = 'alex'
16 session['user2'] = 'alex'
17 del session['user2']
18
19 return "内容"
20
21 if __name__ == '__main__':
22 app.run()
23
24 session.py
25 #!/usr/bin/env python
26 # -*- coding:utf-8 -*-
27 import uuid
28 import json
29 from flask.sessions import SessionInterface
30 from flask.sessions import SessionMixin
31 from itsdangerous import Signer, BadSignature, want_bytes
32
33
34 class MySession(dict, SessionMixin):
35 def __init__(self, initial=None, sid=None):
36 self.sid = sid
37 self.initial = initial
38 super(MySession, self).__init__(initial or ())
39
40
41 def __setitem__(self, key, value):
42 super(MySession, self).__setitem__(key, value)
43
44 def __getitem__(self, item):
45 return super(MySession, self).__getitem__(item)
46
47 def __delitem__(self, key):
48 super(MySession, self).__delitem__(key)
49
50
51
52 class MySessionInterface(SessionInterface):
53 session_class = MySession
54 container = {}
55
56 def __init__(self):
57 import redis
58 self.redis = redis.Redis()
59
60 def _generate_sid(self):
61 return str(uuid.uuid4())
62
63 def _get_signer(self, app):
64 if not app.secret_key:
65 return None
66 return Signer(app.secret_key, salt='flask-session',
67 key_derivation='hmac')
68
69 def open_session(self, app, request):
70 """
71 程序刚启动时执行，需要返回一个session对象
72 """
73 sid = request.cookies.get(app.session_cookie_name)
74 if not sid:
75 sid = self._generate_sid()
76 return self.session_class(sid=sid)
77
78 signer = self._get_signer(app)
79 try:
80 sid_as_bytes = signer.unsign(sid)
81 sid = sid_as_bytes.decode()
82 except BadSignature:
83 sid = self._generate_sid()
84 return self.session_class(sid=sid)
85
86 # session保存在redis中
87 # val = self.redis.get(sid)
88 # session保存在内存中
89 val = self.container.get(sid)
90
91 if val is not None:
92 try:
93 data = json.loads(val)
94 return self.session_class(data, sid=sid)
95 except:
96 return self.session_class(sid=sid)
97 return self.session_class(sid=sid)
98
99 def save_session(self, app, session, response):
100 """
101 程序结束前执行，可以保存session中所有的值
102 如：
103 保存到resit
104 写入到用户cookie
105 """
106 domain = self.get_cookie_domain(app)
107 path = self.get_cookie_path(app)
108 httponly = self.get_cookie_httponly(app)
109 secure = self.get_cookie_secure(app)
110 expires = self.get_expiration_time(app, session)
111
112 val = json.dumps(dict(session))
113
114 # session保存在redis中
115 # self.redis.setex(name=session.sid, value=val, time=app.permanent_session_lifetime)
116 # session保存在内存中
117 self.container.setdefault(session.sid, val)
118
119 session_id = self._get_signer(app).sign(want_bytes(session.sid))
120
121 response.set_cookie(app.session_cookie_name, session_id,
122 expires=expires, httponly=httponly,
123 domain=domain, path=path, secure=secure)
七、Flask之蓝图
蓝图用于为应用提供目录划分：
小型应用程序：示例
大型应用程序：示例
其他：
- 蓝图URL前缀：xxx = Blueprint('account', __name__,url_prefix='/xxx')
- 蓝图子域名：xxx = Blueprint('account', __name__,subdomain='admin')
# 前提需要给配置SERVER_NAME： app.config['SERVER_NAME'] = 'wupeiqi.com:5000'
# 访问时：admin.wupeiqi.com:5000/login.html
八、Flask之message
message是一个基于Session实现的用于保存数据的集合，其特点是：使用一次就删除。（也称为闪现）
from flask import Flask, flash, redirect, render_template, request, get_flashed_messages
app = Flask(__name__)
app.secret_key = 'some_secret'
@app.route('/')
def index1():
messages = get_flashed_messages()
print(messages)
return "Index1"
@app.route('/set')
def index2():
v = request.args.get('p')
flash(v)
return 'ok'
if __name__ == "__main__":
app.run()
1 from flask import Flask, flash, redirect, render_template, request, get_flashed_messages
2
3 app = Flask(__name__)
4 app.secret_key = 'some_secret'
5
6
7 @app.route('/')
8 def index1():
9 messages = get_flashed_messages()
10 print(messages)
11 return "Index1"
12
13
14 @app.route('/set')
15 def index2():
16 v = request.args.get('p')
17 flash(v)
18 return 'ok'
19
20
21 if __name__ == "__main__":
22 app.run()
九、中间件
from flask import Flask, flash, redirect, render_template, request
app = Flask(__name__)
app.secret_key = 'some_secret'
@app.route('/')
def index1():
return render_template('index.html')
@app.route('/set')
def index2():
v = request.args.get('p')
flash(v)
return 'ok'
class MiddleWare:
def __init__(self, wsgi_app):
self.wsgi_app = wsgi_app
def __call__(self, *args, **kwargs):
# 执行前操作
res = self.wsgi_app(*args, **kwargs)
# 执行后操作
return res
if __name__ == "__main__":
app.wsgi_app = MiddleWare(app.wsgi_app)
app.run(port=9999)
1 from flask import Flask, flash, redirect, render_template, request
2
3 app = Flask(__name__)
4 app.secret_key = 'some_secret'
5
6 @app.route('/')
7 def index1():
8 return render_template('index.html')
9
10 @app.route('/set')
11 def index2():
12 v = request.args.get('p')
13 flash(v)
14 return 'ok'
15
16 class MiddleWare:
17 def __init__(self, wsgi_app):
18 self.wsgi_app = wsgi_app
19
20 def __call__(self, *args, **kwargs):
21 # 执行前操作
22 res = self.wsgi_app(*args, **kwargs)
23 # 执行后操作
24 return res
25
26 if __name__ == "__main__":
27 app.wsgi_app = MiddleWare(app.wsgi_app)
28 app.run(port=9999)
十、Flask插件
- Flask-Session
- WTForms
- SQLAchemy
- 等...
