def __init__(self, maxsize=100):
        if not isinstance(maxsize, (int, long)):
            raise TypeError('Expected integer, got %r' % (maxsize, ))
        self.maxsize = maxsize  # Maximum connections (pool + checkout out)
        self.pool = Queue()     # Open connection pool
        self.size = 0           # Number of open connections
dataset/ETHPy150Open ooici/pyon/pyon/datastore/postgresql/pg_util.py/DatabaseConnectionPool.__init__/original