Unable to connect to postgres sever from google colab using psycopg2

i keep getting errors attemping to connect to postgres from google colab,however on pycharm these same code connects to the server easily. Here is the code:

import psycopg2

params = {
    "host"      : "localhost",
    "database"  : "somedb",
    "user"      : "postgres",
    "password"  : "mypassword"
}
def connect(params):
    """ Connect to the PostgreSQL database server """
    conn = None
    try:
        # connect to the PostgreSQL server
        print('Connecting to the PostgreSQL database...')
        conn = psycopg2.connect(**params)
    except (Exception, psycopg2.DatabaseError) as error:
        print(error)
         
    return conn

connect(params)

errors i am getting

OperationalError: could not connect to server: Connection refused
    Is the server running on host "localhost" (127.0.0.1) and accepting
    TCP/IP connections on port 5432?
could not connect to server: Cannot assign requested address
    Is the server running on host "localhost" (::1) and accepting
    TCP/IP connections on port 5432?