how to save/load cookies to/from QNetworkAccessManager

I used QNetworkAccessManager to load pages and login to some sites. I want to save cookies and load them to next using this programm.

I write this code to save cookies:

import shelve
self.netManager=QNetworkAccessManager()
#... Load Pages and Login ....
with shelve.open('LoginDb','c') as db:
    db['cooki']=netManager.CookieJar()

and this code to load cookies:

with shelve.open('LoginDb','c') as db:
    self.netManager.setCookieJar(db['cooki'])

But setCookieJar doesn't work and arise this error:

super-class init() of type QNetworkCookieJar was never called

What can i do to do this?

Solution

That error message typically means you subclassed QNetworkCookieJar and forgot to call the superclass __init__. You should do something like this (assuming Python 3):

class CookieJar(QNetworkCookieJar):

    def __init__(self, parent):
        super().__init__(parent)  # You probably don't do this
        # Do custom stuff here

I'd also advise against using shelve. It's brittle, slow, and in certain scenarios a security risk. I personally just store them in a plaintext file in my project - something like this:

class CookieJar(QNetworkCookieJar):

    # [...]

    def parse_cookies(self):
        cookies = []
        with open('cookies', 'r') as f:
            for line in f:
                cookies += QNetworkCookie.parseCookies(line)
        self.setAllCookies(cookies)

    def save(self):
        with open('cookies', 'w') as f:
            for cookie in self.allCookies():
                if not cookie.isSessionCookie():
                    f.write(cookie.toRawForm() + '\n')