一、Session
1、面向对象基础
面向对象中通过索引的方式访问对象，需要内部实现 __getitem__ 、__delitem__、__setitem__方法
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#!/usr/bin/env python# -*- coding:utf-8 -*- class Foo(object):
def __getitem__(self, key):
print '__getitem__',key
def __setitem__(self, key, value):
print '__setitem__',key,value
def __delitem__(self, key):
print '__delitem__',key
obj = Foo()
result = obj['k1']
#obj['k2'] = 'wupeiqi'#del obj['k1'] |
2、Tornado扩展
Tornado框架中，默认执行Handler的get/post等方法之前默认会执行 initialize方法，所以可以通过自定义的方式使得所有请求在处理前执行操作...
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class BaseHandler(tornado.web.RequestHandler):
def initialize(self):
self.xxoo = "wupeiqi"
class MainHandler(BaseHandler):
def get(self):
print(self.xxoo)
self.write('index')
class IndexHandler(BaseHandler):
def get(self):
print(self.xxoo)
self.write('index')
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3、session
session其实就是定义在服务器端用于保存用户回话的容器，其必须依赖cookie才能实现。
#!/usr/bin/env python
# -*- coding:utf-8 -*-
import config
from hashlib import sha1
import os
import time create_session_id = lambda: sha1(bytes('%s%s' % (os.urandom(16), time.time()), encoding='utf-8')).hexdigest() class SessionFactory: @staticmethod
def get_session_obj(handler):
obj = None if config.SESSION_TYPE == "cache":
obj = CacheSession(handler)
elif config.SESSION_TYPE == "memcached":
obj = MemcachedSession(handler)
elif config.SESSION_TYPE == "redis":
obj = RedisSession(handler)
return obj class CacheSession:
session_container = {}
session_id = "__sessionId__" def __init__(self, handler):
self.handler = handler
client_random_str = handler.get_cookie(CacheSession.session_id, None)
if client_random_str and client_random_str in CacheSession.session_container:
self.random_str = client_random_str
else:
self.random_str = create_session_id()
CacheSession.session_container[self.random_str] = {} expires_time = time.time() + config.SESSION_EXPIRES
handler.set_cookie(CacheSession.session_id, self.random_str, expires=expires_time) def __getitem__(self, key):
ret = CacheSession.session_container[self.random_str].get(key, None)
return ret def __setitem__(self, key, value):
CacheSession.session_container[self.random_str][key] = value def __delitem__(self, key):
if key in CacheSession.session_container[self.random_str]:
del CacheSession.session_container[self.random_str][key] class RedisSession:
def __init__(self, handler):
pass class MemcachedSession:
def __init__(self, handler):
pass
自定义session
4、分布式Session
# -*- coding: utf-8 -*-
"""
hash_ring
~~~~~~~~~~~~~~
Implements consistent hashing that can be used when
the number of server nodes can increase or decrease (like in memcached). Consistent hashing is a scheme that provides a hash table functionality
in a way that the adding or removing of one slot
does not significantly change the mapping of keys to slots. More information about consistent hashing can be read in these articles: "Web Caching with Consistent Hashing":
http://www8.org/w8-papers/2a-webserver/caching/paper2.html "Consistent hashing and random trees:
Distributed caching protocols for relieving hot spots on the World Wide Web (1997)":
http://citeseerx.ist.psu.edu/legacymapper?did=38148 Example of usage:: memcache_servers = ['192.168.0.246:11212',
'192.168.0.247:11212',
'192.168.0.249:11212'] ring = HashRing(memcache_servers)
server = ring.get_node('my_key') :copyright: 2008 by Amir Salihefendic.
:license: BSD
""" import math
import sys
from bisect import bisect if sys.version_info >= (2, 5):
import hashlib
md5_constructor = hashlib.md5
else:
import md5
md5_constructor = md5.new class HashRing(object): def __init__(self, nodes=None, weights=None):
"""`nodes` is a list of objects that have a proper __str__ representation.
`weights` is dictionary that sets weights to the nodes. The default
weight is that all nodes are equal.
"""
self.ring = dict()
self._sorted_keys = [] self.nodes = nodes if not weights:
weights = {}
self.weights = weights self._generate_circle() def _generate_circle(self):
"""Generates the circle.
"""
total_weight = 0
for node in self.nodes:
total_weight += self.weights.get(node, 1) for node in self.nodes:
weight = 1 if node in self.weights:
weight = self.weights.get(node) factor = math.floor((40*len(self.nodes)*weight) / total_weight) for j in range(0, int(factor)):
b_key = self._hash_digest( '%s-%s' % (node, j) ) for i in range(0, 3):
key = self._hash_val(b_key, lambda x: x+i*4)
self.ring[key] = node
self._sorted_keys.append(key) self._sorted_keys.sort() def get_node(self, string_key):
"""Given a string key a corresponding node in the hash ring is returned. If the hash ring is empty, `None` is returned.
"""
pos = self.get_node_pos(string_key)
if pos is None:
return None
return self.ring[ self._sorted_keys[pos] ] def get_node_pos(self, string_key):
"""Given a string key a corresponding node in the hash ring is returned
along with it's position in the ring. If the hash ring is empty, (`None`, `None`) is returned.
"""
if not self.ring:
return None key = self.gen_key(string_key) nodes = self._sorted_keys
pos = bisect(nodes, key) if pos == len(nodes):
return 0
else:
return pos def iterate_nodes(self, string_key, distinct=True):
"""Given a string key it returns the nodes as a generator that can hold the key. The generator iterates one time through the ring
starting at the correct position. if `distinct` is set, then the nodes returned will be unique,
i.e. no virtual copies will be returned.
"""
if not self.ring:
yield None, None returned_values = set()
def distinct_filter(value):
if str(value) not in returned_values:
returned_values.add(str(value))
return value pos = self.get_node_pos(string_key)
for key in self._sorted_keys[pos:]:
val = distinct_filter(self.ring[key])
if val:
yield val for i, key in enumerate(self._sorted_keys):
if i < pos:
val = distinct_filter(self.ring[key])
if val:
yield val def gen_key(self, key):
"""Given a string key it returns a long value,
this long value represents a place on the hash ring. md5 is currently used because it mixes well.
"""
b_key = self._hash_digest(key)
return self._hash_val(b_key, lambda x: x) def _hash_val(self, b_key, entry_fn):
return (( b_key[entry_fn(3)] << 24)
|(b_key[entry_fn(2)] << 16)
|(b_key[entry_fn(1)] << 8)
| b_key[entry_fn(0)] ) def _hash_digest(self, key):
m = md5_constructor()
m.update(key.encode('utf-8'))
# return map(ord, m.digest()) # python 2
return list(m.digest()) # pyhton 3
一致性哈希（hash_ring.py）
from hashlib import sha1
import os, time create_session_id = lambda: sha1('%s%s' % (os.urandom(16), time.time())).hexdigest() class Session(object): session_id = "__sessionId__" def __init__(self, request):
session_value = request.get_cookie(Session.session_id)
if not session_value:
self._id = create_session_id()
else:
self._id = session_value
request.set_cookie(Session.session_id, self._id) def __getitem__(self, key):
# 根据 self._id ，在一致性哈西中找到其对应的服务器IP
# 找到相对应的redis服务器，如： r = redis.StrictRedis(host='localhost', port=6379, db=0)
# 使用python redis api 链接
# 获取数据，即：
# return self._redis.hget(self._id, name) def __setitem__(self, key, value):
# 根据 self._id ，在一致性哈西中找到其对应的服务器IP
# 使用python redis api 链接
# 设置session
# self._redis.hset(self._id, name, value) def __delitem__(self, key):
# 根据 self._id 找到相对应的redis服务器
# 使用python redis api 链接
# 删除，即：
return self._redis.hdel(self._id, name)
session
二、表单（form）验证
在Web程序中往往包含大量的表单验证的工作，如：判断输入是否为空，是否符合规则。
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
<link href="{{static_url("commons.css")}}" rel="stylesheet" />
</head>
<body>
<h1>hello</h1>
<form action="/index" method="post"> <p>hostname: <input type="text" name="host" /> </p>
<p>ip: <input type="text" name="ip" /> </p>
<p>port: <input type="text" name="port" /> </p>
<p>phone: <input type="text" name="phone" /> </p>
<input type="submit" />
</form>
</body>
</html>
HTML
#!/usr/bin/env python
# -*- coding:utf-8 -*- import tornado.ioloop
import tornado.web
from hashlib import sha1
import os, time
import re class MainForm(object):
def __init__(self):
self.host = "(.*)"
self.ip = "^(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}$"
self.port = '(\d+)'
self.phone = '^1[3|4|5|8][0-9]\d{8}$' def check_valid(self, request):
form_dict = self.__dict__
for key, regular in form_dict.items():
post_value = request.get_argument(key)
# 让提交的数据 和 定义的正则表达式进行匹配
ret = re.match(regular, post_value)
print key,ret,post_value class MainHandler(tornado.web.RequestHandler):
def get(self):
self.render('index.html')
def post(self, *args, **kwargs):
obj = MainForm()
result = obj.check_valid(self)
self.write('ok') settings = {
'template_path': 'template',
'static_path': 'static',
'static_url_prefix': '/static/',
'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh',
'login_url': '/login'
} application = tornado.web.Application([
(r"/index", MainHandler),
], **settings) if __name__ == "__main__":
application.listen(8888)
tornado.ioloop.IOLoop.instance().start()
Python
由于验证规则可以代码重用，所以可以如此定义：
#!/usr/bin/env python
# -*- coding:utf-8 -*- import tornado.ioloop
import tornado.web
import re class Field(object): def __init__(self, error_msg_dict, required):
self.id_valid = False
self.value = None
self.error = None
self.name = None
self.error_msg = error_msg_dict
self.required = required def match(self, name, value):
self.name = name if not self.required:
self.id_valid = True
self.value = value
else:
if not value:
if self.error_msg.get('required', None):
self.error = self.error_msg['required']
else:
self.error = "%s is required" % name
else:
ret = re.match(self.REGULAR, value)
if ret:
self.id_valid = True
self.value = ret.group()
else:
if self.error_msg.get('valid', None):
self.error = self.error_msg['valid']
else:
self.error = "%s is invalid" % name class IPField(Field):
REGULAR = "^(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}$" def __init__(self, error_msg_dict=None, required=True): error_msg = {} # {'required': 'IP不能为空', 'valid': 'IP格式错误'}
if error_msg_dict:
error_msg.update(error_msg_dict) super(IPField, self).__init__(error_msg_dict=error_msg, required=required) class IntegerField(Field):
REGULAR = "^\d+$" def __init__(self, error_msg_dict=None, required=True):
error_msg = {'required': '数字不能为空', 'valid': '数字格式错误'}
if error_msg_dict:
error_msg.update(error_msg_dict) super(IntegerField, self).__init__(error_msg_dict=error_msg, required=required) class CheckBoxField(Field): def __init__(self, error_msg_dict=None, required=True):
error_msg = {} # {'required': 'IP不能为空', 'valid': 'IP格式错误'}
if error_msg_dict:
error_msg.update(error_msg_dict) super(CheckBoxField, self).__init__(error_msg_dict=error_msg, required=required) def match(self, name, value):
self.name = name if not self.required:
self.id_valid = True
self.value = value
else:
if not value:
if self.error_msg.get('required', None):
self.error = self.error_msg['required']
else:
self.error = "%s is required" % name
else:
if isinstance(name, list):
self.id_valid = True
self.value = value
else:
if self.error_msg.get('valid', None):
self.error = self.error_msg['valid']
else:
self.error = "%s is invalid" % name class FileField(Field):
REGULAR = "^(\w+\.pdf)|(\w+\.mp3)|(\w+\.py)$" def __init__(self, error_msg_dict=None, required=True):
error_msg = {} # {'required': '数字不能为空', 'valid': '数字格式错误'}
if error_msg_dict:
error_msg.update(error_msg_dict) super(FileField, self).__init__(error_msg_dict=error_msg, required=required) def match(self, name, value):
self.name = name
self.value = []
if not self.required:
self.id_valid = True
self.value = value
else:
if not value:
if self.error_msg.get('required', None):
self.error = self.error_msg['required']
else:
self.error = "%s is required" % name
else:
m = re.compile(self.REGULAR)
if isinstance(value, list):
for file_name in value:
r = m.match(file_name)
if r:
self.value.append(r.group())
self.id_valid = True
else:
self.id_valid = False
if self.error_msg.get('valid', None):
self.error = self.error_msg['valid']
else:
self.error = "%s is invalid" % name
break
else:
if self.error_msg.get('valid', None):
self.error = self.error_msg['valid']
else:
self.error = "%s is invalid" % name def save(self, request, upload_path=""): file_metas = request.files[self.name]
for meta in file_metas:
file_name = meta['filename']
with open(file_name,'wb') as up:
up.write(meta['body']) class Form(object): def __init__(self):
self.value_dict = {}
self.error_dict = {}
self.valid_status = True def validate(self, request, depth=10, pre_key=""): self.initialize()
self.__valid(self, request, depth, pre_key) def initialize(self):
pass def __valid(self, form_obj, request, depth, pre_key):
"""
验证用户表单请求的数据
:param form_obj: Form对象（Form派生类的对象）
:param request: Http请求上下文（用于从请求中获取用户提交的值）
:param depth: 对Form内容的深度的支持
:param pre_key: Html中name属性值的前缀（多层Form时，内部递归时设置，无需理会）
:return: 是否验证通过，True：验证成功；False：验证失败
""" depth -= 1
if depth < 0:
return None
form_field_dict = form_obj.__dict__
for key, field_obj in form_field_dict.items():
print key,field_obj
if isinstance(field_obj, Form) or isinstance(field_obj, Field):
if isinstance(field_obj, Form):
# 获取以key开头的所有的值，以参数的形式传至
self.__valid(field_obj, request, depth, key)
continue
if pre_key:
key = "%s.%s" % (pre_key, key) if isinstance(field_obj, CheckBoxField):
post_value = request.get_arguments(key, None)
elif isinstance(field_obj, FileField):
post_value = []
file_list = request.request.files.get(key, None)
for file_item in file_list:
post_value.append(file_item['filename'])
else:
post_value = request.get_argument(key, None) print post_value
# 让提交的数据 和 定义的正则表达式进行匹配
field_obj.match(key, post_value)
if field_obj.id_valid:
self.value_dict[key] = field_obj.value
else:
self.error_dict[key] = field_obj.error
self.valid_status = False class ListForm(object):
def __init__(self, form_type):
self.form_type = form_type
self.valid_status = True
self.value_dict = {}
self.error_dict = {} def validate(self, request):
name_list = request.request.arguments.keys() + request.request.files.keys()
index = 0
flag = False
while True:
pre_key = "[%d]" % index
for name in name_list:
if name.startswith(pre_key):
flag = True
break
if flag:
form_obj = self.form_type()
form_obj.validate(request, depth=10, pre_key="[%d]" % index)
if form_obj.valid_status:
self.value_dict[index] = form_obj.value_dict
else:
self.error_dict[index] = form_obj.error_dict
self.valid_status = False
else:
break index += 1
flag = False class MainForm(Form): def __init__(self):
# self.ip = IPField(required=True)
# self.port = IntegerField(required=True)
# self.new_ip = IPField(required=True)
# self.second = SecondForm()
self.fff = FileField(required=True)
super(MainForm, self).__init__() #
# class SecondForm(Form):
#
# def __init__(self):
# self.ip = IPField(required=True)
# self.new_ip = IPField(required=True)
#
# super(SecondForm, self).__init__() class MainHandler(tornado.web.RequestHandler):
def get(self):
self.render('index.html')
def post(self, *args, **kwargs):
# for i in dir(self.request):
# print i
# print self.request.arguments
# print self.request.files
# print self.request.query
# name_list = self.request.arguments.keys() + self.request.files.keys()
# print name_list # list_form = ListForm(MainForm)
# list_form.validate(self)
#
# print list_form.valid_status
# print list_form.value_dict
# print list_form.error_dict # obj = MainForm()
# obj.validate(self)
#
# print "验证结果：", obj.valid_status
# print "符合验证结果：", obj.value_dict
# print "错误信息:"
# for key, item in obj.error_dict.items():
# print key,item
# print self.get_arguments('favor'),type(self.get_arguments('favor'))
# print self.get_argument('favor'),type(self.get_argument('favor'))
# print type(self.get_argument('fff')),self.get_argument('fff')
# print self.request.files
# obj = MainForm()
# obj.validate(self)
# print obj.valid_status
# print obj.value_dict
# print obj.error_dict
# print self.request,type(self.request)
# obj.fff.save(self.request)
# from tornado.httputil import HTTPServerRequest
# name_list = self.request.arguments.keys() + self.request.files.keys()
# print name_list
# print self.request.files,type(self.request.files)
# print len(self.request.files.get('fff')) # obj = MainForm()
# obj.validate(self)
# print obj.valid_status
# print obj.value_dict
# print obj.error_dict
# obj.fff.save(self.request)
self.write('ok') settings = {
'template_path': 'template',
'static_path': 'static',
'static_url_prefix': '/static/',
'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh',
'login_url': '/login'
} application = tornado.web.Application([
(r"/index", MainHandler),
], **settings) if __name__ == "__main__":
application.listen(8888)
tornado.ioloop.IOLoop.instance().start()