redis基本操作

'''
pip install redis

redis 可以看成内存中的大字典

redis五大数据类型 --> 指的是第一层的value值的类型
    - 字符串       "k1"
    - 列表        [11,22,33，11]
    - 集合        {11,22,33}
    - 字典        {
                    'kk1':vv1,
                    'kk2':vv2,
                    'kk3':{}  这个value不能是字典，如果有需要，则需要转换成字符串的形式。
                }
    - 有序集合      {('alex',4),('standby',3),('egon',9)}
'''

import redis

conn = redis.Redis(host='10.0.0.2',port=6379)

# 字符串
conn.set('k1','v1',ex=10)
conn.get('k1')

# 列表
# 可以当消息队列来使用
conn.lpush('users','alex')
conn.rpush('users','eric')
conn.lpop('users')
conn.rpop('users')

# 双向队列，可以hang住，可以模拟栈和队列，  爬虫，爬网页-广度优先和深度优先
conn.blpop('users',timeout=10)
conn.brpop('users',timeout=10)

conn.expire('key','超时时间')

count = conn.llen('users')
print(count)

vals = conn.lrange('users',0,10)
print(vals)

# redis针对列表类型，没有提供 iter 方法，需要自己实现
def list_scan_iter(key):
    # count = conn.llen(key)
    start = 0
    step = 3
    while True:
        vals = conn.lrange(key,start,start+step)
        start = start + step + 1
        if not vals:
            return
        for val in vals:
            yield val

result = list_scan_iter('users')
for item in result:
    print(item)

# 集合

# 哈希

# 有序结合

遍历DB

import redis

conn = redis.StrictRedis(host='8.8.8.8', port=6379, db=8, password='1234567890')

cursor_num, keys = conn.execute_command('scan', 0, "count", 100)

while True:
    print keys
    if 0==int(cursor_num):
        break
    cursor_num, keys = conn.execute_command('scan', cursor_num, "count", 100)

　　

Django通过redis实现session共享示例

安装插件 Django 1.11 以上版本才可以使用

pip2.7 install django-redis

配置插件

SESSION_ENGINE = 'django.contrib.sessions.backends.cache'
SESSION_CACHE_ALIAS = 'default'

CACHES = {
    "default": {
        "BACKEND": "django_redis.cache.RedisCache",
        "LOCATION": "redis://10.10.10.10:6379",
        "OPTIONS": {
            "CLIENT_CLASS": "django_redis.client.DefaultClient",
            "CONNECTION_POOL_KWARGS": {"max_connections": 100},
            "PASSWORD": "your_password_for_redis",
        }
    }
}

使用redis

from django_redis import get_redis_connection
conn = get_redis_connection("default")

使用redis存储session信息

class UserAuth(object):
    def __init__(self, request, response=None, user=None, autologin=None):
        self.request = request
        self.response = response
        if user:
            self.uid = str(user.id)
            self.name = str(user.username)
        self.autologin = autologin
        self.sessionkey = None
        self.logger = get_logger('UserAuth')

    def session_check(self):
        self.sessionkey = self.request.COOKIES.get('yoursessionkey', None)
        if self.sessionkey and conn.exists('yoursessionkey_%s' % self.sessionkey):
            return conn.hget('yoursessionkey_%s' % self.sessionkey, 'userinfo')
        return None

    def set_cookie_session(self):
        self.sessionkey = self.request.COOKIES.get('yoursessionkey', None)
        ttl = 60*60*24 if self.autologin else 60*60
        if not self.sessionkey:
            # set cookie
            h = hashlib.md5()
            h.update(str(int(time.time())))
            self.sessionkey = h.hexdigest()
            self.response.set_cookie('yoursessionkey', h.hexdigest(), max_age=ttl)
            self.logger.error('New sessionid: {} for {}'.format(self.sessionkey,self.name))

        key = 'yoursessionkey_%s' % self.sessionkey
        if not conn.exists(key):
            # set session
            conn.hset(key, 'userinfo', '_'.join([self.name,self.uid]))
            conn.expire(key,ttl)
            self.logger.error('New redis key: {}, ttl: {}'.format(key,ttl))
        return True

登录的视图函数

def verify(raw_password,encoded):
    # 以PBKDF2PasswordHasher这个算法为例
    from django.contrib.auth.hashers import PBKDF2PasswordHasher
    hasher = PBKDF2PasswordHasher()
    algorithm, iterations, salt, hash = encoded.split('$', 3)
    encoded2 = hasher.encode(raw_password, salt, int(iterations))
    return encoded == encoded2

class LoginForm(forms.Form):
    username = forms.CharField()
    password = forms.CharField(widget=forms.PasswordInput)
    autologin = forms.BooleanField(required=False)
    next = forms.CharField(widget=forms.HiddenInput)

def user_login(request):
    next = request.GET.get('next',reverse('index'))
    if 'POST' == request.method:
        form = LoginForm(request.POST)
        if form.is_valid():
            name = form.cleaned_data['username']
            pwd = form.cleaned_data['password']
            autologin = form.cleaned_data['autologin']
            user = UserInfo.objects.filter(username=name)
            if user[0] and verify(pwd,user[0].password):
                response = redirect(next)
                user_auth = UserAuth(request, response, user[0], autologin)
                if user_auth.set_cookie_session():
                    user.update(last_login=time.strftime("%Y-%m-%d %H:%M:%S", time.localtime()))
                    return response
            context = {'form':form,'errors':'用户名或密码错误'}
            return render(request,'login.html',context)
        else:
            context = {'form':form,'errors':'用户名或密码不能为空'}
            return render(request,'login.html',context)
    form = LoginForm({'next':next})
    context = {'form':form}
    return render(request,'login.html',context)

登录验证中间件

import re
from django.shortcuts import redirect
from django.utils.deprecation import MiddlewareMixin
from django.conf import settings

class UserAuthMiddleware(MiddlewareMixin):
    def process_request(self,request):
        # Set white list which not check login
        current_request_url = request.path_info
        for url in settings.VALID_URL_LIST:
            if re.match(url, current_request_url):
                return None
        user_auth = UserAuth(request)
        if user_auth.session_check():
            return None
        else:
            import urllib
            params = urllib.urlencode({'next':request.path_info})
            return redirect('/userlogin' + "?" + params)

　　

参考：Python操作 RabbitMQ、Redis、Memcache、SQLAlchemy