अन्य उत्तर इस तरह के सत्र को बनाए रखने के तरीके को समझने में मदद करते हैं। इसके अतिरिक्त, मैं एक वर्ग प्रदान करना चाहता हूं जो सत्र को स्क्रिप्ट के विभिन्न रनों के साथ बनाए रखता है (कैश फ़ाइल के साथ)। इसका मतलब है कि एक उचित "लॉगिन" केवल तब ही किया जाता है जब आवश्यकता होती है (कैश में कोई समय या कोई सत्र मौजूद नहीं है)। इसके अलावा यह 'पाने' या 'पोस्ट' करने के लिए बाद की कॉल पर प्रॉक्सी सेटिंग्स का समर्थन करता है।
इसका परीक्षण पायथन 3 के साथ किया गया है।
इसे अपने कोड के लिए एक आधार के रूप में उपयोग करें। निम्नलिखित स्निपेट GPL v3 के साथ जारी किए जाते हैं
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
उपरोक्त वर्ग का उपयोग करने के लिए एक कोड स्निपेट इस तरह दिख सकता है:
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)