[Sqlalchemy-tickets] Issue #3701: cymysql fails in get_isolation_level during engine.connect() (zzzeek/sqlalchemy)

[John V. <iss...@bi...>]

New issue 3701: cymysql fails in get_isolation_level during engine.connect()
https://bitbucket.org/zzzeek/sqlalchemy/issues/3701/cymysql-fails-in-get_isolation_level

John Vandenberg:

While connecting, the following error occurs.

```
==================================== ERRORS ====================================
______________________ ERROR at setup of test_2010_count _______________________
request = <SubRequest 'connection' for <Function 'test_2010_count'>>
engine = Engine(mysql+cymysql://travis@localhost/era_data)
    @pytest.fixture(scope="module")
    def connection(request, engine):
>       connection = engine.connect()
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/pytest_sqlalchemy.py:27: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py:2018: in connect
    return self._connection_cls(self, **kwargs)
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py:72: in __init__
    if connection is not None else engine.raw_connection()
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py:2104: in raw_connection
    self.pool.unique_connection, _connection)
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py:2074: in _wrap_pool_connect
    return fn()
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/pool.py:318: in unique_connection
    return _ConnectionFairy._checkout(self)
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/pool.py:713: in _checkout
    fairy = _ConnectionRecord.checkout(pool)
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/pool.py:480: in checkout
    rec = pool._do_get()
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/pool.py:1060: in _do_get
    self._dec_overflow()
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/util/langhelpers.py:60: in __exit__
    compat.reraise(exc_type, exc_value, exc_tb)
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/pool.py:1057: in _do_get
    return self._create_connection()
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/pool.py:323: in _create_connection
    return _ConnectionRecord(self)
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/pool.py:454: in __init__
    exec_once(self.connection, self)
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/event/attr.py:246: in exec_once
    self(*args, **kw)
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/event/attr.py:256: in __call__
    fn(*args, **kw)
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/util/langhelpers.py:1319: in go
    return once_fn(*arg, **kw)
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/engine/strategies.py:165: in first_connect
    dialect.initialize(c)
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/dialects/mysql/base.py:2633: in initialize
    default.DefaultDialect.initialize(self, connection)
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/engine/default.py:249: in initialize
    self.get_isolation_level(connection.connection)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
self = <sqlalchemy.dialects.mysql.cymysql.MySQLDialect_cymysql object at 0x1db15d0>
connection = <cymysql.connections.Connection object at 0x1db19d0>
    def get_isolation_level(self, connection):
        cursor = connection.cursor()
        cursor.execute('SELECT @@tx_isolation')
        val = cursor.fetchone()[0]
        cursor.close()
        if util.py3k and isinstance(val, bytes):
            val = val.decode()
>       return val.upper().replace("-", " ")
E       AttributeError: 'NoneType' object has no attribute 'upper'
../../../virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/sqlalchemy/dialects/mysql/base.py:2502: AttributeError
```

https://travis-ci.org/jayvdb/era_data/jobs/127444574