Summary: Support selecion session/otk data store. Add redis as data store. Allow admin to select the backend data store. Compatibility matrix: main\/ session>| anydbm | sqlite | redis | mysql | postgresql | anydbm | D | | X | | | sqlite | X | D | X | | | mysql | | | | D | | postgresql | | | | | D | --------------------------------------------------------------+ D - default if unconfigured, X - compatible choice DETAILS roundup/configuration.py: add config.ini section sessiondb with settings: backend and redis_url. CHANGES.txt, doc/admin_guide.txt, doc/installation.txt, doc/upgrading.txt: doc on config of session db and redis. Plus some other fixes: admin - clarified why we do not drop __words and __testids table in native-fts conversion. TYpo fix. upgrading - doc how you can keep using anydbm for session data with sqlite. Fix dupe sentence in an upgrading config.ini section. roundup/backends/back_anydbm.py, roundup/backends/back_sqlite.py: code to support redis, redis/anydbm backends respectively. roundup/backends/sessions_redis.py new storage backend for redis. roundup/rest.py, roundup/cgi/actions.py, roundup/cgi/templating.py redis uses a different way of calculating lifetime/timestamp. Since expiration of an item occurred if its timestamp was more than 1 week old, code would calculate: now - 1 week + lifetime. But this results in faster expiration in redis if used for lifetime/timestamp. Convert code to use the lifetime() method in BasicDatabase that generates the right timestamp for each backend. test/session_common.py: added tests for more cases, get without default, getall non-existing key etc. timestamp test changed to use new self.get_ts which is overridden in other tests. Test that datatypes survive storage. test/test_redis_session.py: test redis session store with sqlite and anydbm primary databases test/test_anydbm.py, test/test_sqlite.py add test to make sure the databases are properly set up sqlite - add test cases where anydbm is used as datastore anydbm - remove updateTimestamp override add get_ts(). test/test_config.py tests on redis_url and compatibility on choice of sessiondb backend .travis.yml: add redis db and redis-py

"""
In Python 3, sometimes TAL "python:" expressions that refer to
variables but not all variables are recognized. That is in Python 2.7
all variables used in a TAL "python:" expression are recognized as
references. In Python 3.5 (perhaps earlier), some TAL "python:"
expressions refer to variables but the reference generates an error
like this:

<class 'NameError'>: name 'some_tal_variable' is not defined

even when the variable is defined. Output after this message lists the
variable and its value.
"""

import unittest

from roundup.cgi.PageTemplates.PythonExpr import PythonExpr as PythonExprClass

class ExprTest(unittest.TestCase):
    def testExpr(self):
        expr = '[x for x in context.assignedto ' \
               'if x.realname not in user_realnames]'
        pe = PythonExprClass('test', expr, None)
        # Looking at the expression, only context and user_realnames are
        # external variables. The names assignedto and realname are members,
        # and x is local.
        required_names = ['context', 'user_realnames']
        got_names = pe._f_varnames
        for required_name in required_names:
            self.assertIn(required_name, got_names)