Here's my code:

from bitcoin.rpc import RawProxy
# Create a connection to local Bitcoin Core node
p = RawProxy()
# Run the getinfo command, store the resulting data in info
info = p.getinfo()
# Retrieve the 'blocks' element from the info
print(info['blocks'])

I could execute the RPC using curl:

➜  bitcoin git:(master) curl --user glaksmono --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "getwalletinfo", "params": [] }' -H 'content-type: text/plain;' http://127.0.0.1:18332
Enter host password for user 'glaksmono':
{"result":{"walletname":"wallet.dat","walletversion":159900,"balance":0.00000000,"unconfirmed_balance":0.00000000,"immature_balance":0.00000000,"txcount":0,"keypoololdest":1523932637,"keypoolsize":999,"keypoolsize_hd_internal":1000,"paytxfee":0.00000000,"hdmasterkeyid":"6e64f10c7c94532b597feaec70369df40ae84023"},"error":null,"id":"curltest"}

I've also installed python-bitcoinlib successfully:

➜  Sandbox pip install python-bitcoinlib
Collecting python-bitcoinlib
  Downloading https://files.pythonhosted.org/packages/30/03/fb7df95fe89baede202cf3fe65e65bea4bf863061b5e8f59b12dab538240/python_bitcoinlib-0.10.1-py2.py3-none-any.whl (88kB)
    100% |████████████████████████████████| 92kB 1.5MB/s
Installing collected packages: python-bitcoinlib

Ideas how should I execute the RPC through the Python code?

The result of my script and the python and pip versions are below:

➜  Sandbox pip --version
pip 10.0.0 from /Library/Python/2.7/site-packages/pip (python 2.7)
➜  Sandbox python --version
Python 3.6.4

➜  Sandbox python rpc_example.py
Traceback (most recent call last):
  File "rpc_example.py", line 1, in <module>
    from bitcoin.rpc import RawProxy
ModuleNotFoundError: No module named 'bitcoin'