cx_Oracle.DatabaseError: ORA-12541: TNS:no listener

[ARV]

I am getting this error while connecting DB

import cx_Oracle
connection = cx_Oracle.connect("USERNAME", "PWD", "HOST/DEV")

Operating System: Windows7
Python version : 3.7.4-64 bit
Oracle Client: 11.2.0
PyCharm: x64

In my desktop i have multiple clients are installed-Oracle10g, 11g, R12c

Is this causing the problem.

Is there anyway to set listener path connecting to DB through PyCharm

[buran]

Maybe this could help
https://stackoverflow.com/questions/1335...o-listener

[ARV]

My issue is resolved after adding the port number to host name

import cx_Oracle
connection = cx_Oracle.connect("USERNAME", "PWD", "HOST:PORT NUMBER/DEV")