Description of problem:
The combination of pyodbc-4.0.30, mariadb-server-10.3.27-3 and mariadb-connector-odbc-3.0.7-1 leads to the issue, which makes pyodbc unusable(exec method every time fails).
Every query attempt returns : pyodbc.DataError: ('22018', ' [ma-3.0.7][10.3.27-MariaDB]Invalid character value for cast specification (0) (SQLExecDirectW)')
Version-Release number of selected component (if applicable):
install mariadb-server-10.3.27-3, mariadb-connector-odbc, unixODBC, pyodbc
set up correctly drivers
run a simple query via pyodbc API
Reproducer available here 
I have reviewed the doc text and I have no suggestions for changes.