Can't set or get documents from a server remotely

I got a Couchbase server and I want to insert data to the bucket there using Python SDK library.

Using this link
I can set the username and the password.

However, when I try to set and get documents using Python SDK library, I got exception.

This is my code:
from couchbase import Couchbase
connection = Couchbase.connect(bucket=‘data’, host=‘’)

The connection works fine, but when I try this:
connection.set(‘key’, ‘value’)
I got this exception:
Traceback (most recent call last):
File “”, line 1, in
File “C:\Python27\lib\site-packages\couchbase\”, line 331, in set
persist_to, replicate_to)
_ConnectError_0x18 (generated, catch ConnectError): <Key=u’key’, RC=0x18[Error while establishing TCP connection], Operational Error, Results=1, C Source=(src\multiresult.c,286)>

What wrong did I do please?
Please note that I am using password to access the server from the URL, but in Python SDK I didn’t specify any password because I am following your official tutorial here

The Python SDK client library is installed on Windows 7 64bit, with python 2.7 32bit

The firewall is off and I can successfully set and get document to a my local Couchbase server. my problem is with the remotely Couchbase server

Could you help me please?