学习使用rabbitmq，遇到麻烦

• python3.3.2
• rabbitmq3.4.1
• pika-0.9.14

python send.py

 Traceback (most recent call last):
  File "send.py", line 3, in <module>
    connection = pika.BlockingConnection(pika.ConnectionParameters(host='localhost'))
  File "/home/hawk/g/sqlalchemy/lib/python3.3/site-packages/pika/connection.py", line 361, in __init__
    if host and self._validate_host(host):
  File "/home/hawk/g/sqlalchemy/lib/python3.3/site-packages/pika/connection.py", line 207, in _validate_host
    if not isinstance(host, basestring):
NameError: global name 'basestring' is not defined
------------------------------------------------------------
python receive.py 
Traceback (most recent call last):
  File "receive.py", line 5, in <module>
    host='localhost'))
  File "/home/hawk/g/sqlalchemy/lib/python3.3/site-packages/pika/connection.py", line 361, in __init__
    if host and self._validate_host(host):
  File "/home/hawk/g/sqlalchemy/lib/python3.3/site-packages/pika/connection.py", line 207, in _validate_host
    if not isinstance(host, basestring):
NameError: global name 'basestring' is not defined

这是什么情况？