user32636: When I run the script
from bitcoin.core import COIN, b2lx
import bitcoin.wallet
import bitcoin.rpc

rpc = bitcoin.rpc.Proxy()
addr = bitcoin.wallet.CBitcoinAddress('mfrMeTKojpEXFXpcQiRr7zA3Bff4UBgZTx')

txid = rpc.sendtoaddress(addr, 0.001 * COIN)
print(b2lx(txid))

I get the following ERROR
CannotSendRequest                         Traceback (most recent call last)
<ipython-input-23-904d1d3102d7> in <module>()
----> 1 txid = rpc.sendtoaddress(addr, 0.001 * COIN)

/home/remote_user/unix_practice/python-bitcoinlib/bitcoin/rpc.py in sendtoaddress(self, addr, amount)
    557         addr = str(addr)
    558         amount = float(amount)/COIN
--> 559         r = self._call('sendtoaddress', addr, amount)
    560         return lx(r)
    561 

/home/remote_user/unix_practice/python-bitcoinlib/bitcoin/rpc.py in _call(self, service_name, *args)
    150                              'User-Agent': DEFAULT_USER_AGENT,
    151                              'Authorization': self.__auth_header,
--> 152                              'Content-type': 'application/json'})
    153 
    154         response = self._get_response()

/usr/lib64/python2.7/httplib.pyc in request(self, method, url, body, headers)
    971     def request(self, method, url, body=None, headers={}):
    972         """Send a complete request to the server."""
--> 973         self._send_request(method, url, body, headers)
    974 
    975     def _set_content_length(self, body):

/usr/lib64/python2.7/httplib.pyc in _send_request(self, method, url, body, headers)
    999             skips['skip_accept_encoding'] = 1
   1000 
-> 1001         self.putrequest(method, url, **skips)
   1002 
   1003         if body is not None and 'content-length' not in header_names:

/usr/lib64/python2.7/httplib.pyc in putrequest(self, method, url, skip_host, skip_accept_encoding)
    869             self.__state = _CS_REQ_STARTED
    870         else:
--> 871             raise CannotSendRequest()
    872 
    873         # Save the method we use, we need it later in the response phase

CannotSendRequest:

Any idea how to resolve this? I used the code from 
Sample Post

user3478: The issue was that addr is being provided an invalid address - a Main Net address does not work on Test Net, and vice versa.  (From the edit revisions history, the code sample you provided was using bitcoin.wallet.CBitcoinAddress('1JwSSubhmg6iPtRjtyqhUYYH7bZg3Lfy1T') which would provide a Main Net address)
Replace the address being supplied in the addr variable with a legitimate Test Net address, and it should work.

32636: <p>When I run the script</p>

<pre><code>from bitcoin.core import COIN, b2lx
import bitcoin.wallet
import bitcoin.rpc

rpc = bitcoin.rpc.Proxy()
addr = bitcoin.wallet.CBitcoinAddress('mfrMeTKojpEXFXpcQiRr7zA3Bff4UBgZTx')

txid = rpc.sendtoaddress(addr, 0.001 * COIN)
print(b2lx(txid))
</code></pre>

<p>I get the following ERROR</p>

<pre><code>CannotSendRequest                         Traceback (most recent call last)
&lt;ipython-input-23-904d1d3102d7&gt; in &lt;module&gt;()
----&gt; 1 txid = rpc.sendtoaddress(addr, 0.001 * COIN)

/home/remote_user/unix_practice/python-bitcoinlib/bitcoin/rpc.py in sendtoaddress(self, addr, amount)
    557         addr = str(addr)
    558         amount = float(amount)/COIN
--&gt; 559         r = self._call('sendtoaddress', addr, amount)
    560         return lx(r)
    561 

/home/remote_user/unix_practice/python-bitcoinlib/bitcoin/rpc.py in _call(self, service_name, *args)
    150                              'User-Agent': DEFAULT_USER_AGENT,
    151                              'Authorization': self.__auth_header,
--&gt; 152                              'Content-type': 'application/json'})
    153 
    154         response = self._get_response()

/usr/lib64/python2.7/httplib.pyc in request(self, method, url, body, headers)
    971     def request(self, method, url, body=None, headers={}):
    972         """Send a complete request to the server."""
--&gt; 973         self._send_request(method, url, body, headers)
    974 
    975     def _set_content_length(self, body):

/usr/lib64/python2.7/httplib.pyc in _send_request(self, method, url, body, headers)
    999             skips['skip_accept_encoding'] = 1
   1000 
-&gt; 1001         self.putrequest(method, url, **skips)
   1002 
   1003         if body is not None and 'content-length' not in header_names:

/usr/lib64/python2.7/httplib.pyc in putrequest(self, method, url, skip_host, skip_accept_encoding)
    869             self.__state = _CS_REQ_STARTED
    870         else:
--&gt; 871             raise CannotSendRequest()
    872 
    873         # Save the method we use, we need it later in the response phase

CannotSendRequest:
</code></pre>

<p>Any idea how to resolve this? I used the code from </p>

<p><a href="https://bitcoin.stackexchange.com/questions/24571/how-to-make-a-simple-payment-with-the-python-bitcoinlib/24661#24661">Sample Post</a></p>
 3478: <p>The issue was that <code>addr</code> is being provided an invalid address - a Main Net address does not work on Test Net, and vice versa.  (From the edit revisions history, the code sample you provided was using <code>bitcoin.wallet.CBitcoinAddress('1JwSSubhmg6iPtRjtyqhUYYH7bZg3Lfy1T')</code> which would provide a Main Net address)</p>

<p>Replace the address being supplied in the <code>addr</code> variable with a legitimate Test Net address, and it should work.</p>
