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Using python to get DB2 list db directory on a remote server

I want to get the list of DBs on a remote server with a python script.
I know I can connect to a certain db with
import ibm_db
ibm_db.connect("DATABASE=name;HOSTNAME=host;PORT=60000;PROTOCOL=TCPIP;UID=username;
PWD=password;", "", "")
however I want to only connect to an instance and then do "db2 list db directory" to get the DB names.
Meaning change to the instance user and set off that command or preferably use a python module that can do just that. I only need the names no real connection to a database.
The result should be an array with all database names in that instance.
Any ideas or help?
Thank you

Unfortunately, there is no such function in python-ibmdb API and actually not even in full Db2 API. The only "workaround" I could think of would be UDF deployed on the remote database that uses db2DbDirOpenScan to access the catalog and return the info via the connection that is already established.

Connecting to Oracle DB in python without using 3rd parties

I'm trying to connect to an Oracle database within a python script, I'm not allowed to use any 3rd party imports/downloads, only the python standard library, like cx_oracle, which is the only solution to this I've found. I'm not super familiar with oracle databases, could someone explain how to connect and query without using cx_oracle and things like it.

Sourced from the documentation:
https://cx-oracle.readthedocs.io/en/latest/installation.html#quick-start-cx-oracle-installation
Example:
import cx_Oracle
# Connect as user "hr" with password "welcome"
# to the "oraclepdb" service running on this computer.
connection = cx_Oracle.connect("hr", "welcome", "localhost/orclpdb")
cursor = connection.cursor()
cursor.execute("""
SELECT first_name, last_name
FROM employees
WHERE department_id = :did AND employee_id > :eid""",
did = 50,
eid = 190)
for fname, lname in cursor:
print("Values:", fname, lname)

Oracle's network protocol isn't public so you need either (i) some Oracle technology installed on your computer that knows that protocol - this is cx_Oracle and Oracle Instant Client (ii) or something like Oracle's ORDS product running on the database which will let you use REST calls.
If you need to interact with an Oracle Database you could make a very strong argument that you need to install cx_Oracle and Oracle Instant Client. cx_Oracle is on PyPI so it can be installed like any other Python package you need. Instant Client needs to be installed separately, but is the Oracle product that you could be expected to require to connect to Oracle DB.

why should we set the local_infile=1 in sqlalchemy to load local file? Load file not allowed issue in sqlalchemy

I am using sqlalchemy to connect to MySQL database and found a strange behavior.
If I query
LOAD DATA LOCAL INFILE
'C:\\\\Temp\\\\JaydenW\\\\iata_processing\\\\icer\\\\rename\\\\ICER_2017-10-
12T09033
7Z023870.csv
It pops an error:
sqlalchemy.exc.InternalError: (pymysql.err.InternalError) (1148, u'The used
command is not allowed with this MySQL versi
on') [SQL: u"LOAD DATA LOCAL INFILE
'C:\\\\Temp\\\\JaydenW\\\\iata_processing\\\\icer\\\\rename\\\\ICER_2017-10-
12T090337Z023870.csv' INTO TABLE genie_etl.iata_icer_etl LINES TERMINATED BY
'\\n'
IGNORE 1 Lines (rtxt);"] (Background on this error at:
http://sqlalche.me/e/2j85)
And I find the reason is that:
I need to set the parameter as
args = "mysql+pymysql://"+username+":"+password+"#"+hostname+"/"+database+"?
local_infile=1"
If I use MySQL official connection library. I do not need to do so.
myConnection = MySQLdb.connect(host=hostname, user=username, passwd=password, db=database)
Can anyone help me to understand the difference between the two mechanisms?

The reason is that the mechanisms use different drivers.
In SQLAlchemy you appear to be using the pymysql engine, which uses the PyMySQL Connection class to create the DB connection. That one requires the user to explicitly pass the local_infile parameter if they want to use the LOAD DATA LOCAL command.
The other example uses MySQLdb, which is basically a wrapper around the MySQL C API (and to my knowledge not the official connection library; that would be MySQL Connector Python, which is also available on SQLAlchemy as mysqlconnector). This one apparently creates the connection in a way that the LOAD DATA LOCAL is enabled by default.

SQLAlchemy orm styles, how to make special drive to your connection string

I use pypy, pypyodbc and SQLAlchemy.
I have problem of odbc connections.
I use:
engine = create_engine('mssql+pyodbc://dbuser:dbpasswd#localhost/dbname', echo = False)
Session = sessionmaker(bind=engine)
style try to connect the database.
The error is:
C:\pypy\site-packages\sqlalchemy\connectors\pypyodbc.py:82: SAWarning: No driver
name specified; this is expected by PyODBC when using DSN-less connections
"No driver name specified; "
The reason of this error, I find the connect parameter
DRIVER={SQL Server Native Client}
is not transmit to the engine, in other word, I want to know how to set DRIVER string for this connections style for SQLALchemy.

I've run into the same issue with Sybase ASE and after looking at the pyodbc.py source code you can pass GET-like parameters in your url. As an example (working for me):
sybase+pyodbc://username:password#hostname:5000/dbname?driver=Adaptive Server Enterprise
It's also sort of documented here with the connection string syntax being dialect://user:password#host/dbname[?key=value..]
Hope that helps

You may have also be been suffering from updating your SqlAlchemy version. As of the latest release (v1.0) you need to explicitly define your driver in the connection string for Microsoft SQL Server.
See:
Changed in version 1.0.0: Hostname-based PyODBC connections now require the SQL Server driver name specified explicitly. SQLAlchemy cannot choose an optimal default here as it varies based on platform and installed drivers.
http://docs.sqlalchemy.org/en/latest/dialects/mssql.html#hostname-connections
See:
Connecting to database using SQLAlchemy

I had this error message and fixed it by adding this to the end of the connection string:
"?driver=SQL+Server+Native+Client+10.0"

Connect to SQL Server instance using pymssql

I'm attempting to connect to a SQL Server instance from a Windows box using pymssql (version 2.0.0b1-dev-20111019 with Python 2.7.1). I've tried the most basic approach from the console:
import pymssql
c = pymssql.connect(host = r'servername\instance',
user = 'username',
password = 'userpassword')
In response to this, I get the very helpful error: InterfaceError: Connection to the database failed for an unknown reason.
I am reasonably confident that the connection information is correct, as it works when I use adodbapi, with the following commands:
import adodbapi
c = adodbapi.connect(r'Provider=sqloledb;Data Source=servername\instance;User ID=username;password=userpassword;'
c.close
I've tried adding the port number to the host parameter, with the same result. Does anyone have a suggestion on how to go about resolving this issue?
Incidentally, I've read the responses at "Unable to connect to SQL Server via pymssql". The OP eventually resolved his issue by correctly configuring FreeTDS, which, from what I can tell, is not used by pymssql on Windows.
Based on #cha0site's recommendation, I have tried using just the hostname, rather than the hostname and instance. This resulted in the same error, but it seemed to take longer to generate the error (though the traceback still indicates the same line). The reason I have been specifying the instance is that I was not able to connect using SSMS unless I specified the instance, so I assumed that it would be necessary for other connections.
I've now also tried pymssql.connect(host='servername', user='username', password='userpassword', database='instance') with the same result (based on #Sid's comment). Based on the pymssql documentation, I believe the database parameter is used to specify the initial database that the user is to be connected to, rather than the instance.
Just to clarify, "instance" is the name provided during installation of SQL Server, not a database within that installation. It occurs to me that it's possible that pymssql does not support this notation, so I will look into re-configuring the SQL Server instance so that it is not required.
I've now re-installed SQL Server as a default instance, rather than a named instance, which allows me to connect without specifying the instance name. adodbapi still works (without /instance), but pymssql still returns the same error. I've also removed and re-installed pymssql from a freshly downloaded archive (still the same version).

Check your freetds.conf file and see if you have set the port 1219., then check again the connexion:
DB = pymssql.connect(host='DB',user='youruser',password='yourpwd',database='yourDBname')
Edit: example of my freetds.conf file Python:
host = 'IP'
port = 1219

To specify host=servername\instance or server=servername\instance, the SQL Server Browser service must be on the SQL Server machine.