Python请求和持久会话


119

我正在使用请求模块(Python 2.5的版本0.10.0)。我已经找到了如何将数据提交到网站上的登录表单并检索会话密钥的方法,但是我看不到在后续请求中使用此会话密钥的明显方法。有人可以在下面的代码中填写省略号还是建议其他方法?

>>> import requests
>>> login_data =  {'formPosted':'1', 'login_email':'me@example.com', 'password':'pw'}
>>> r = requests.post('https://localhost/login.py', login_data)
>>> 
>>> r.text
u'You are being redirected <a href="profilePage?_ck=1349394964">here</a>'
>>> r.cookies
{'session_id_myapp': '127-0-0-1-825ff22a-6ed1-453b-aebc-5d3cf2987065'}
>>> 
>>> r2 = requests.get('https://localhost/profile_data.json', ...)

Answers:


209

您可以使用以下方法轻松创建持久会话:

s = requests.Session()

之后,继续执行您的请求,如下所示:

s.post('https://localhost/login.py', login_data)
#logged in! cookies saved for future requests.
r2 = s.get('https://localhost/profile_data.json', ...)
#cookies sent automatically!
#do whatever, s will keep your cookies intact :)

有关会话的更多信息:https : //requests.kennethreitz.org/en/master/user/advanced/#session-objects


4
有什么方法可以在脚本运行之间保存Session本身?
Gtx

10
可以pickle.dump会话cookie到pickle.dump(session.cookies._cookies,file)这样的文件,pickle.load到如下会话的cookie = pickle.load(file)cj = request.cookies.RequestsCookieJar()cj._cookies = Cookie和session.cookies = cj
西里尔

如果我涉及代理人怎么办?
brainLoop

1
对于发送到的请求localhost,如果它们包含不正确的域属性值,则登录名和Web服务器返回的其他Cookie可能会出现问题。对于localhost,Web服务器应返回Domain属性设置为localhost.local的cookie,否则cookie不会应用于会话。在这种情况下使用127.0.0.1的,而不是localhost
谢尔盖Nudnov

@SergeyNudnov非常感谢您的评论,我浪费了大量时间试图弄清楚会话为什么无法正确处理Cookie。将域从localhost更改为localhost.local可以解决此问题。再次感谢。
Pulkownik

25

其他答案有助于了解如何维护此类会话。另外,我想提供一个类,该类可以使会话在脚本的不同运行(带有缓存文件)上维护。这意味着仅在需要时才执行正确的“登录”(超时或缓存中不存在会话)。它还支持在随后的“ get”或“ post”调用中的代理设置。

已通过Python3测试。

使用它作为您自己的代码的基础。以下代码段随GPL v3一起发布

import pickle
import datetime
import os
from urllib.parse import urlparse
import requests    

class MyLoginSession:
    """
    a class which handles and saves login sessions. It also keeps track of proxy settings.
    It does also maintine a cache-file for restoring session data from earlier
    script executions.
    """
    def __init__(self,
                 loginUrl,
                 loginData,
                 loginTestUrl,
                 loginTestString,
                 sessionFileAppendix = '_session.dat',
                 maxSessionTimeSeconds = 30 * 60,
                 proxies = None,
                 userAgent = 'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:40.0) Gecko/20100101 Firefox/40.1',
                 debug = True,
                 forceLogin = False,
                 **kwargs):
        """
        save some information needed to login the session

        you'll have to provide 'loginTestString' which will be looked for in the
        responses html to make sure, you've properly been logged in

        'proxies' is of format { 'https' : 'https://user:pass@server:port', 'http' : ...
        'loginData' will be sent as post data (dictionary of id : value).
        'maxSessionTimeSeconds' will be used to determine when to re-login.
        """
        urlData = urlparse(loginUrl)

        self.proxies = proxies
        self.loginData = loginData
        self.loginUrl = loginUrl
        self.loginTestUrl = loginTestUrl
        self.maxSessionTime = maxSessionTimeSeconds
        self.sessionFile = urlData.netloc + sessionFileAppendix
        self.userAgent = userAgent
        self.loginTestString = loginTestString
        self.debug = debug

        self.login(forceLogin, **kwargs)

    def modification_date(self, filename):
        """
        return last file modification date as datetime object
        """
        t = os.path.getmtime(filename)
        return datetime.datetime.fromtimestamp(t)

    def login(self, forceLogin = False, **kwargs):
        """
        login to a session. Try to read last saved session from cache file. If this fails
        do proper login. If the last cache access was too old, also perform a proper login.
        Always updates session cache file.
        """
        wasReadFromCache = False
        if self.debug:
            print('loading or generating session...')
        if os.path.exists(self.sessionFile) and not forceLogin:
            time = self.modification_date(self.sessionFile)         

            # only load if file less than 30 minutes old
            lastModification = (datetime.datetime.now() - time).seconds
            if lastModification < self.maxSessionTime:
                with open(self.sessionFile, "rb") as f:
                    self.session = pickle.load(f)
                    wasReadFromCache = True
                    if self.debug:
                        print("loaded session from cache (last access %ds ago) "
                              % lastModification)
        if not wasReadFromCache:
            self.session = requests.Session()
            self.session.headers.update({'user-agent' : self.userAgent})
            res = self.session.post(self.loginUrl, data = self.loginData, 
                                    proxies = self.proxies, **kwargs)

            if self.debug:
                print('created new session with login' )
            self.saveSessionToCache()

        # test login
        res = self.session.get(self.loginTestUrl)
        if res.text.lower().find(self.loginTestString.lower()) < 0:
            raise Exception("could not log into provided site '%s'"
                            " (did not find successful login string)"
                            % self.loginUrl)

    def saveSessionToCache(self):
        """
        save session to a cache file
        """
        # always save (to update timeout)
        with open(self.sessionFile, "wb") as f:
            pickle.dump(self.session, f)
            if self.debug:
                print('updated session cache-file %s' % self.sessionFile)

    def retrieveContent(self, url, method = "get", postData = None, **kwargs):
        """
        return the content of the url with respect to the session.

        If 'method' is not 'get', the url will be called with 'postData'
        as a post request.
        """
        if method == 'get':
            res = self.session.get(url , proxies = self.proxies, **kwargs)
        else:
            res = self.session.post(url , data = postData, proxies = self.proxies, **kwargs)

        # the session has been updated on the server, so also update in cache
        self.saveSessionToCache()            

        return res

使用上述类的代码片段可能如下所示:

if __name__ == "__main__":
    # proxies = {'https' : 'https://user:pass@server:port',
    #           'http' : 'http://user:pass@server:port'}

    loginData = {'user' : 'usr',
                 'password' :  'pwd'}

    loginUrl = 'https://...'
    loginTestUrl = 'https://...'
    successStr = 'Hello Tom'
    s = MyLoginSession(loginUrl, loginData, loginTestUrl, successStr, 
                       #proxies = proxies
                       )

    res = s.retrieveContent('https://....')
    print(res.text)

    # if, for instance, login via JSON values required try this:
    s = MyLoginSession(loginUrl, None, loginTestUrl, successStr, 
                       #proxies = proxies,
                       json = loginData)

6
这是一个很好的答案,而且很难找到这种解决方案。
二元性

不应作为请求模块的一部分实现吗?
user1602

它确实使用该requests模块。您将如何实现它作为模块的一部分?或@ user1602是什么意思?
DomTomCat

17

在这个类似的问题中查看我的答案:

python:urllib2如何使用urlopen请求发送cookie

import urllib2
import urllib
from cookielib import CookieJar

cj = CookieJar()
opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj))
# input-type values from the html form
formdata = { "username" : username, "password": password, "form-id" : "1234" }
data_encoded = urllib.urlencode(formdata)
response = opener.open("https://page.com/login.php", data_encoded)
content = response.read()

编辑:

我看到我的回答有些不满意,但没有解释性的评论。我猜是因为我指的是urllib库而不是requests。我这样做是因为OP寻求帮助requests或有人建议其他方法。


2
我不是您的反对者之一,但是据推测,许多读者可能会掩饰OP的最后一句话:“有人可以在下面的代码中填写省略号,还是可以建议另一种方法[使用请求库,其中涉及更多主要内容而不是仅仅用其他东西填充省略号]。” -但这只是我的猜测。
布兰登·罗兹

7
作为OP,我可以说您的答案提供了一个有用的选择。如果只是为了证明它requests为问题提供了一个简单而高级的解决方案,否则将需要3个库来实现。
ChrisGuest 2015年


6

尝试了以上所有答案后,我发现使用“ RequestsCookieJar”代替常规的CookieJar处理后续请求可以解决我的问题。

import requests
import json

# The Login URL
authUrl = 'https://whatever.com/login'

# The subsequent URL
testUrl = 'https://whatever.com/someEndpoint'

# Logout URL
testlogoutUrl = 'https://whatever.com/logout'

# Whatever you are posting
login_data =  {'formPosted':'1', 
               'login_email':'me@example.com', 
               'password':'pw'
               }

# The Authentication token or any other data that we will receive from the Authentication Request. 
token = ''

# Post the login Request
loginRequest = requests.post(authUrl, login_data)
print("{}".format(loginRequest.text))

# Save the request content to your variable. In this case I needed a field called token. 
token = str(json.loads(loginRequest.content)['token'])  # or ['access_token']
print("{}".format(token))

# Verify Successful login
print("{}".format(loginRequest.status_code))

# Create your Requests Cookie Jar for your subsequent requests and add the cookie
jar = requests.cookies.RequestsCookieJar()
jar.set('LWSSO_COOKIE_KEY', token)

# Execute your next request(s) with the Request Cookie Jar set
r = requests.get(testUrl, cookies=jar)
print("R.TEXT: {}".format(r.text))
print("R.STCD: {}".format(r.status_code))

# Execute your logout request(s) with the Request Cookie Jar set
r = requests.delete(testlogoutUrl, cookies=jar)
print("R.TEXT: {}".format(r.text))  # should show "Request Not Authorized"
print("R.STCD: {}".format(r.status_code))  # should show 401

1
谢谢@ jim-chertkov!即使几年后,答案也很好!我能够使用和理解这一点。
JayRizzo

2

片段以获取受密码保护的json数据

import requests

username = "my_user_name"
password = "my_super_secret"
url = "https://www.my_base_url.com"
the_page_i_want = "/my_json_data_page"

session = requests.Session()
# retrieve cookie value
resp = session.get(url+'/login')
csrf_token = resp.cookies['csrftoken']
# login, add referer
resp = session.post(url+"/login",
                  data={
                      'username': username,
                      'password': password,
                      'csrfmiddlewaretoken': csrf_token,
                      'next': the_page_i_want,
                  },
                  headers=dict(Referer=url+"/login"))
print(resp.json())

1

仅保存所需的cookie并重复使用。

import os
import pickle
from urllib.parse import urljoin, urlparse

login = 'my@email.com'
password = 'secret'
# Assuming two cookies are used for persistent login.
# (Find it by tracing the login process)
persistentCookieNames = ['sessionId', 'profileId']
URL = 'http://example.com'
urlData = urlparse(URL)
cookieFile = urlData.netloc + '.cookie'
signinUrl = urljoin(URL, "/signin")
with requests.Session() as session:
    try:
        with open(cookieFile, 'rb') as f:
            print("Loading cookies...")
            session.cookies.update(pickle.load(f))
    except Exception:
        # If could not load cookies from file, get the new ones by login in
        print("Login in...")
        post = session.post(
            signinUrl,
            data={
                'email': login,
                'password': password,
            }
        )
        try:
            with open(cookieFile, 'wb') as f:
                jar = requests.cookies.RequestsCookieJar()
                for cookie in session.cookies:
                    if cookie.name in persistentCookieNames:
                        jar.set_cookie(cookie)
                pickle.dump(jar, f)
        except Exception as e:
            os.remove(cookieFile)
            raise(e)
    MyPage = urljoin(URL, "/mypage")
    page = session.get(MyPage)

0

这将在Python中为您工作;

# Call JIRA API with HTTPBasicAuth
import json
import requests
from requests.auth import HTTPBasicAuth

JIRA_EMAIL = "****"
JIRA_TOKEN = "****"
BASE_URL = "https://****.atlassian.net"
API_URL = "/rest/api/3/serverInfo"

API_URL = BASE_URL+API_URL

BASIC_AUTH = HTTPBasicAuth(JIRA_EMAIL, JIRA_TOKEN)
HEADERS = {'Content-Type' : 'application/json;charset=iso-8859-1'}

response = requests.get(
    API_URL,
    headers=HEADERS,
    auth=BASIC_AUTH
)

print(json.dumps(json.loads(response.text), sort_keys=True, indent=4, separators=(",", ": ")))
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