title: python can not use .pgpass while connecting to PostgreSQL
body: <p>I can not use .pgpass file while connecting to postgresql db using python script(((
  My python script to connect is without password:</p>
  
  <pre><code>conn = psycopg2.connect("dbname='postgres' user='postgres' host='192.168.136.129'");
  </code></pre>
  
  <p>My <strong>.pgpass:</strong></p>
  
  <pre><code>*:*:*:postgres:password
  </code></pre>
  
  <p>is located in <strong>/var/lib/postgresql</strong> - home directory for postgres user.
  However when I connect to db locally:</p>
  
  <pre><code>psql -U postgres
  </code></pre>
  
  <p>no password is asked. But for python error is raised:</p>
  
  <pre><code>root@debian:/python_codes/Junior/Level1/DB1/Generator_py# python connect_db.py 
  Unable to connect to db...
  Traceback (most recent call last):
    File "connect_db.py", line 34, in connectdb
      conn = psycopg2.connect("dbname='postgres' user='postgres' host='192.168.136.129'");
    File "/usr/lib/python2.7/dist-packages/psycopg2/__init__.py", line 179, in connect
      connection_factory=connection_factory, async=async)
  OperationalError: fe_sendauth: no password supplied
  </code></pre>