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pyodbc + PostgreSQL ODBC: connection string works, DSN doesn't

I am trying to connect to a Postgres DB built for a Django app. I can connect fine in windows, but when we moved it over to a Linux server for production it stopped working. I tracked it down to pyodbc not working. So in a separate script, I have been trying to get a connection working with no luck. I'm pretty sure the Linux server is running Redhat (yum is the install, but I can double check if it matters)
Here are some of the things I have tried:
installed unixODBC-devel
added a DSN to the user sourcename /home/localUsername/.odbc.ini file as follows:
[DSNName]
Description=Postgres Connection to Database
Driver=/usr/pgsql-10/lib/psqlodbc.so
Server=servername
Database=dbname
PWD=pass
UID=username
Running odbcinst -q -d returns:
[PostgreSQL]
python script I have tried (although using interpreter for now)
con = odbc.connect("DSN=DSNName")
con = odbc.connect("Driver={PostgreSQL};Uid=username;Pwd=pass; Server=servername;Port=5432)
con = odbc.connect("Driver={PostgreSQL Unicode(x64)};Uid=username;Pwd=pass; Server=servername;Port=5432)
I get one of three errors depending on which driver I try:
For the Driver using Unicode(x32) I get:
pyodbc.Error ('01000', "[01000] [unixODBC][Driver Manager]can't open lib 'PostgreSQL Unicode(x32)' : file not found ...
I figure that means this driver is not installed which is fine.
For the DSN approach I get:
pyodbc.OperationalError: ('08001', '[08001] FATAL: role:"localUsername" does not exists\n (101) (SQLDriverConnect)')
This second error seems to make me think (maybe incorrectly) that it is trying to use my localUsername to authenticate to Postgres, when I want to use a special admin username that was setup for the host for now.
For the third option (PostgreSQL):
pyodbc.OperationalError 08001 FATAL: database "dbname" does not exist
I don't understand why that might be? My first thought is Linux wants to use a different port for connection. Locally on windows I can use the 5432 port and it worked fine. So I'm at a loss on how to get it to find the DB assuming the rest is working okay.
If you need additional details let me know and I'll try to add them.
Edit:
Have python (and Django) on one server. DB is on another.
Tried running psql -h OSServername -U 'username' with the same: role error/DB not found errors. I feel like I must be needing something after OSServername like 'OsServername/pgAdminServer' but that didn't work
where db 'username' is found by right clicking inside of pgAdmin one of the DB server names and selecting properties. Are the Server names inside pgAdmin different and do I need to somehow use the pgAdmin Server Name as part of the connection string?
As the comments suggest, starting with the psql -h command seems like a good place to start as it gets rid of the python complexity. Once I can get that command working, I might be able to fix the rest. What do I type when my Linux server name (Host name) is 'LinuxName', pgAdmin Server is 'pgAdminServer', the actual DB has a name 'dbName', and the pgAdmin username is 'username'. 'dbName' has an owner 'owner' which is different from the username of the pgServer as well as different from the Linux username I am signed in as. I also validated that the 'pgAdminServer' shows port 5432, so that shouldn't be the issue.
Edit 2:
I got the pyodbc.connect('Driver={PostgreSQL};Server=servNm;Uid=uid;pwd=pwd;Database=db') to work.
Now just need the last step for the DSN approach. Your dump_dsn worked to find a typo in my dsn file (.odbc.ini in my local home directory). So that helped. Still not finding the DB.
File in: /etc/odbcinst.ini list the following drivers which I have tried all three in my DSN file:
/usr/pgsql-10/lib/psqlodbc.so
/usr/pgsql-10/lib/psqlodbca.so
/usr/pgsql-10/lib/psqlodbcw.so
here is the info again from my .odbc.ini file in home/user/.odbc.ini:
variables: servNm, uid, db, and pwd match exactly with those found in my pyodbc.connect() string now working.
[DSNName]
Description=Postgres Connection to Database
Driver=/usr/pgsql-10/lib/psqlodbc.so
Server=servNm
CommLog=0
Debug=0
Fetch=100
UniqueIndex=1
UseDeclareFetch=0
Database=db
UID=uid
Username=uid
PWD=pwd
ReadOnly=0

Deleting and re-creating the ~/.odbc.ini file appears to have resolved the issue. This makes us suspect that there were one or more unusual characters in the previous version of that file that were causing strange behaviour.
One possible source of such troublesome (and sometimes even invisible!) characters is when copying text from the web. If we copy the following from our web browser …
DRIVER=PostgreSQL Unicode
… and paste it into a blank document in our text editor with the default encoding UTF-8 then everything looks normal. However, if we save that file (as UTF-8) and open it in a hex editor we can see that the space is not a normal space (U+0020) …
… it is a NO-BREAK SPACE (a.k.a. "NBSP", U+00A0, \xc2\xa0 in UTF-8 encoding) so the chances are very good that we would get an error when trying to use that DSN because b'PostgreSQL\xc2\xa0Unicode' is not the same as b'PostgreSQL Unicode'.

I had the exact same problem. I looked for several solutions, but none worked.
The problem was solved more easily than I thought:
1 - Remove all packages about postgresodbc:
$ sudo apt-get remove odbc-postgresql
2 - Install two libs, in the same order below:
$ apt-get install libcppdb-postgresql0 odbc-postgresql
Enjoy!
Doing so worked perfectly here.

MySQL connection error message after deployment in Pythonanywhere

I deployed my python program in pythonanywhere. This program should be connected to MySQL. I set up the database and I configured my database setting in the config.ini file as below:
[mysql]
host =psedemo.mysql.pythonanywhere-services.com
database =psedemo$psedemo_test
user =psedemo
password =QAZwsx123
When I am running the program from the shell, I am getting the following error in database connection:
"Exception - 1142 (42000): SELECT command denied to user 'psedemo'#'10.0.0.207' for table 'pseapp_osd_products'".
Any idea what is the issue? (I am sure that databases/table are created and my setting also is right)

I am changing my answer as I reviewed Pythonanywhere just now. It looks like you have created a python app there and you are using the MySQL db from them. Your password for Pythonanywhere is different from the MySQL password. When you first generate the database, they ask you to create a password for it and mention that it is different from your Pythonanywhere password. You can create a new password in the database page in case you forgot the password.
Click on your database name in their UI to launch the mysql console. Check the following command.
SHOW GRANTS;
It will most probably show that your user has all the GRANTS.
Now, use the connection details on the page, and the password you created, and try to connect again.
You can also check their help page to connect to MySQL https://help.pythonanywhere.com/pages/UsingMySQL/

try using user = "root" for your user

Another source of this error could be a typo in a join. See some of the discussion here and check that the query you're running is correct.

python psycopg2 postgresql: getting "permission denied for relation settings"

I have been through numerous other posts (to name only a few) but still stuck. The configuration is simple enough that I'll detail everything, though I think only a few of the following are relevant:
Running psql as user postgres on Ubuntu 16.04, I've created database qedadmin with 3 tables: networks, devices, and settings; there's also a sequence relation networks_networkid_seq owned by networks.networkId.
I am writing a python script to run on the same server using psycopg2 which needs to execute a SELECT on the settings table. Many examples show scripts connecting as user 'postgres', and indeed this works perfectly for me. However, I suppose it's better to use a less-privileged user for this sort of thing, so I created a user qedserver with a password.
Using this new user and password and localhost in the psycopg2 connection string, I can successfully get a connection and a cursor (and if I use incorrect user or password values, the connection fails, so I know the defined user and password and the authentication from python are all working). However, all of my attempts to execute a SELECT statement on table settings are returning code 42501: permission denied for relation settings.
I initially granted user qedserver only SELECT privileges, and only on table settings:
GRANT SELECT ON settings TO qedserver;
Since that did not work, I've gradually escalated privileges to the point that now user qedserver has ALL PRIVILEGES on all 3 tables, on the sequence relation, and on the database:
GRANT ALL PRIVILEGES ON settings TO qedserver;
GRANT ALL PRIVILEGES ON devices TO qedserver;
GRANT ALL PRIVILEGES ON networks TO qedserver;
GRANT ALL PRIVILEGES ON networks_networkid_seq TO qedserver;
GRANT ALL PRIVILEGES ON DATABASE qedadmin TO qedserver;
but I am still getting "permission denied for relation settings".
To be clear, changing just the connection string in my python script from one for user postgres to one for user qedserver makes the difference between success and failure, so I am not providing python code because I think it's irrelevant (but I can do so if you think it would help).
What am I missing?
Edited to add: there is no linux user named qedserver; I don't think there needs to be but perhaps I'm wrong about that? (further edit: I just did this experiment and it made no difference.)
Updates: Per #klin's comment and link, I can see that all of the privileges have been successfully granted: qedserver has privileges arwdDxt on the networks, devices, and settings tables, and rwU privileges on the networks_networkid_seq sequence relation; and \l reports Access Privileges on the qedadmin database of =Tc/postgres + postgres=CTc/postgres + qedserver=CTc/postgres.
I have also edited the config file (/etc/postgresql/10/main/postgresql.conf on my system) to set log_error_verbosity=VERBOSE and sent a SIGHUP to the postgresql process to re-read the config file. This added another line to the error log (/var/log/postgresql/postgresql-10-main.log on my system) for each failed attempt; now the log shows (the new line is the middle one):
qedserver#qedadmin ERROR: 42501: permission denied for relation settings
qedserver#qedadmin LOCATION: aclcheck_error, aclchk.c:3410
qedserver#qedadmin STATEMENT: SELECT * FROM settings WHERE deviceId = 10020;
What else can I look at or try to make headway?
Editing 4 months later to add: this was all for a new project for which I thought it would be advantageous to use postgresql for a few reasons; hitting this problem so early in development and being unable to resolve it over several days, I gave up and went with mysql instead. Not exactly a "solution" to the OP so I'm not adding it as an answer...

change user's privileges on mysql using sqlalchemy

Hi I need to create an user in mysql using sqlalchemy: I am able to check the existence of the user before creating it and create it if it does not exist but when i try to gran t all the privileges on the db I get this error
eTypeError: not enough arguments for format string
thos are the instructions that I use:
self.engine.execute("CREATE USER 'metmi' IDENTIFIED BY 'metmi'")`
and
`self.engine.execute("GRANT ALL PRIVILEGES ON *.* TO metmi#'\%' IDENTIFIED BY 'metmi'")`
if I use the same instruction on phpMyadmin or on the mysql prompt it works, so I am really puzzled, do not know what is wrong;
can somebody tell me what is my error?
thankls in advance

I Solved I had tocreate the same user on localhost, for the internal process of Mysql

Connect to a Sybase database in Python without a DSN?

I'm trying to connect to a Sybase database in Python (using the python-sybase DBAPI and sqlalchemy module), and I'm currently receiving the following error:
ct_connect(): directory service layer: internal directory control layer error: There was an error encountered while binding to the directory service
Here's the code:
import sqlalchemy
connect_url = sqlalchemy.engine.url.URL(drivername='pysybase', username='read_only', password='*****', host='hostname', port=9000, database='tablename', query=None)
db = sqlalchemy.create_engine(connect_url)
connection = db.connect()
I've also tried to connect without sqlalchemy - ie, just importing the Python Sybase module directly and attempting to connect, but I still get the same error.
I've done quite a bit of googling and searching here on SO and at the doc sites for each of the packages I'm using. One common suggestion was to verify the DSN settings, as that's what's causing ct_connect() to trip up, but I am able to connect to and view the database in my locally-installed copy of DBArtisan just fine, and I believe that uses the same DSN.
Perhaps I should attempt to connect in a way without a DSN? Or is there something else I'm missing here?
Any ideas or feedback are much appreciated, thank you!

I figured out the issue for anyone else who might be having a similar problem.
Apparently, even though I had valid entries for the hostname in my sql.ini file and DSN table, Sybase was not reading it correctly - I had to open DSEdit (one of the tools that comes with Sybase) and re-enter the server/hostname info.