gistfile1.txt

# === blah.py ====
import pymongo
print "Version", pymongo.version
servers = "mongodb://localhost:27017,localhost:27018,localhost:27019/?slaveok=true"
DBNAME = "my-db"
COLLECTION = "User"
con = pymongo.Connection(servers)
db = con[DBNAME] 
collection = db[COLLECTION]

for x in collection.find():
    print x

# === the shell ====

$ python blah.py 
Version 1.9+
Traceback (most recent call last):
  File "blah.py", line 10, in <module>
    for x in collection.find():
  File "/Library/Python/2.6/site-packages/pymongo/cursor.py", line 601, in next
    if len(self.__data) or self._refresh():
  File "/Library/Python/2.6/site-packages/pymongo/cursor.py", line 564, in _refresh
    self.__query_spec(), self.__fields))
  File "/Library/Python/2.6/site-packages/pymongo/cursor.py", line 533, in __send_message
    self.__tz_aware)
  File "/Library/Python/2.6/site-packages/pymongo/helpers.py", line 98, in _unpack_response
    raise AutoReconnect("master has changed")
pymongo.errors.AutoReconnect: master has changed