Pyodbc error Data source name not found and no default driver specified paradox

You need a Microsoft Office version compatible with your Python installation, i.e. both of them must be either 32 bit or 64 bit. From the pyodbc documentation:

There are actually two (2) different Access ODBC drivers from Microsoft:

1. Microsoft Access Driver (*.mdb) - This is the older 32-bit "Jet" ODBC driver. It is included as a standard part of a Windows install. It only works with .mdb (not .accdb) files. It is also officially deprecated.

2. Microsoft Access Driver (*.mdb, *.accdb) - This is the newer "ACE" ODBC driver. It is not included with Windows, but it is normally included as part of a Microsoft Office install. It is also available as a free stand-alone "redistributable" installer for machines without Microsoft Office. There are separate 64-bit and 32-bit versions of the "ACE" Access Database Engine (and drivers), and normally one has either the 64-bit version or the 32-bit version installed. (It is possible to force both versions to exist on the same machine but it is not recommended as it can "break" Office installations. Therefore, if you already have Microsoft Office it is highly recommended that you use a Python environment that matches the "bitness" of the Office install.)

The easiest way to check if one of the Microsoft Access ODBC drivers is available to your Python environment (on Windows) is to do

>>> import pyodbc
>>> [x for x in pyodbc.drivers() if x.startswith('Microsoft Access Driver')]

If you see an empty list then you are running 64-bit Python and you need to install the 64-bit version of the "ACE" driver. If you only see ['Microsoft Access Driver (*.mdb)'] and you need to work with an .accdb file then you need to install the 32-bit version of the "ACE" driver.

Two thoughts on what to check:

1) Your connection string is wrong. There's a way to get a known good connection string directly from the ODBC Administrator program (taken from http://www.visokio.com/kb/db/dsn-less-odbc). These instructions assume you're using an MDB, but the same process will work for a paradox file

• On a typical client PC, open Control Panel -> Administrative Tools -> Data Sources.
• Select the File DSN tab and click Add.
• Select the appropriate driver (e.g. "Microsoft Access Driver (*.mdb)") and click Next
• Click Browse and choose where you want to save the .dsn file (this is a temporary file you are going to delete later).
• Click Next then Finish.
• You will be shown the vendor-specific ODBC setup dialog. For example, with Microsoft Access, you might only need to click Select and browse to an existing .mdb file before clicking OK.
• Browse to the location of the .dsn file and open using Notepad.

In the DSN file you might see something similar to:

[ODBC]
DRIVER=Microsoft Access Driver (*.mdb)
UID=admin
UserCommitSync=Yes
Threads=3
SafeTransactions=0
PageTimeout=5
MaxScanRows=8
MaxBufferSize=2048
FIL=MS Access
DriverId=25
DefaultDir=C:\
DBQ=C:\db1.mdb

To convert the above to the full connection strring:

1. Omit the first [ODBC] line
2. Put curly braces around all values containing spaces
3. Put all name=value pairs on one line, separated by semicolons.

This gives you the full connection string. In this example, the string becomes:

DRIVER={Microsoft Access Driver (*.mdb)};UID=admin;UserCommitSync=Yes;Threads=3;SafeTransactions=0;PageTimeout=5;axScanRows=8;MaxBufferSize=2048;FIL={MS Access};DriverId=25;DefaultDir=C:\;DBQ=C:\db1.mdb

2) 32/64 bit mismatch. I've had troubles when mixing 32-bit python with 64-bit drivers, or vice-versa. You may want to check your Python interpreter and database driver line up.