Solución:
Puede crear fácilmente una sesión persistente usando:
s = requests.Session()
Después de eso, continúe con sus solicitudes como lo haría:
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 :)
Para más información sobre las sesiones: https://requests.kennethreitz.org/en/master/user/advanced/#session-objects
las otras respuestas ayudan a comprender cómo mantener dicha sesión. Además, quiero proporcionar una clase que mantenga la sesión mantenida en diferentes ejecuciones de un script (con un archivo de caché). Esto significa que un “inicio de sesión” adecuado solo se realiza cuando es necesario (tiempo de espera o no existe sesión en la caché). También es compatible con la configuración de proxy en las siguientes llamadas a “obtener” o “publicar”.
Está probado con Python3.
Úselo como base para su propio código. Los siguientes fragmentos se publican con GPL v3
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:[email protected]: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
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
Un fragmento de código para usar la clase anterior puede tener este aspecto:
if __name__ == "__main__":
# proxies = {'https' : 'https://user:[email protected]:port',
# 'http' : 'http://user:[email protected]: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)
Mira mi respuesta en esta pregunta similar:
python: urllib2 cómo enviar cookies con solicitud urlopen
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()
EDITAR:
Veo que he recibido algunos votos negativos por mi respuesta, pero no hay comentarios explicativos. Supongo que es porque me refiero al urllib bibliotecas en lugar de requests. Hago eso porque el OP pide ayuda con requests o que alguien sugiera otro enfoque.