Can't connect on postgres in docker container

I'm using Docker on Windows to use in local a postgres database. I made two docker container: one for the database called pg and another called pgadmin with pgadmin4. After inspected pg, I connected pgadmin4 in 172.17.0.3:5432 and it works. Now time to code but...

psycopg2.OperationalError: could not connect to server: Connection timed out (0x0000274C/10060)
        Is the server running on host "172.17.0.3" and accepting
        TCP/IP connections on port 5432?

I read a lot of questions like that, but i can't figure it out. Doesn't seem, to me, like a problem generated in pg_hba.conf for the denied connection, because in this case pgadmin should not work, right? (But if is a problem with pg_hba.conf where I can find it? In the docker installation folder I did't find it)

I put my python code here but don't seems the problem:

conn = psycopg2.connect(
    database = 'example',
    user = 'username',
    password = 'secretpassword',
    host = '172.17.0.3', # default port is 5432 so it's not necessary
)

Upgrade edit: I found the configurations In postgresql.conf the listen_addresses = '*', that is correct. In pg_hba.conf:

# TYPE  DATABASE        USER            ADDRESS                 METHOD

# "local" is for Unix domain socket connections only
local   all             all                                     trust
# IPv4 local connections:
host    all             all             127.0.0.1/32            trust
# IPv6 local connections:
host    all             all             ::1/128                 trust
# Allow replication connections from localhost, by a user with the
# replication privilege.
local   replication     all                                     trust
host    replication     all             127.0.0.1/32            trust
host    replication     all             ::1/128                 trust

You could use docker run and the --expose parameter to expose your ports, on each container.

Another command you can run is docker network connect which allows you to connect a container to a network, so if two containers are on the same network, they should be able to communicate with each other.

The usage is docker network connect [OPTIONS] NETWORK CONTAINER

One advantage of using the docker network create command is to be able to create an --ip-range so to specify ip addresses to be used on the network.

Afterwards you can assign a container to have a specific ip address, docker network connect. If the container was not on the network for example, the ip address would not be reassigned to another container on the network.

More information in the docker documentation, https://docs.docker.com/engine/reference/commandline/network_connect/