refer a string or list global variable in python

Question

In python 2.7.2 + tornado 3.1.1, how to use a global variable? I need it work on AppEngine.

class LoginHandler(BaseHandler):
    def get(self):
        if self.get_current_user():
            self.redirect('/')
            return
        # assign self.get_argument('next', '/')) to the variable next_page
        self.render('login.html')

    def post(self):
        self.set_secure_cookie("user", self.get_argument("username"))
        # direct to next_page

Tornado will not work on App Engine. And you certainly don't want a global variable on either App Engine or Tornado. — Daniel Roseman, Nov 30 '13 at 14:57
yep, it may be a bad idea running tornado on AppEngine. But tornado supports WSGI and AppEngine do too. @Daniel Roseman — Gray, Nov 30 '13 at 15:06

greg · Accepted Answer · 2013-11-30T15:10:44.847

2

You don't need global variables for store next_page variable. Try to use sessions or memcache for it.

from google.appengine.api import memcache

# setup a key/value
memcache.set(key='next_page_%s' % user.id, next_page)

# get next_page
next_page = memcache.get(key='next_page_%s' % user.id)

We use 'next_page_%s' % user.id with user.id for unigue key, otherwise every user will have only one next_page.

edited Nov 30 '13 at 15:10

answered Nov 30 '13 at 14:52

greg

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score 1 · Answer 2 · edited May 23 '17 at 10:25

1

You need to assign the variable as being global within each function:

global globalvariable

See also Using global variables in a function other than the one that created them for more information on this issue.

edited May 23 '17 at 10:25

Community

1
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answered Nov 30 '13 at 14:48

fuesika

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refer a string or list global variable in python

2 Answers2