Connect to an AS/400 (iSeries) using ODBC.

as400_odbc.py

import pyodbc

class CommitMode:
    NONE = 0 #Commit immediate (*NONE)  --> QSQCLIPKGN
    CS = 1 #Read committed (*CS)        --> QSQCLIPKGS
    CHG = 2 #Read uncommitted (*CHG)    --> QSQCLIPKGC
    ALL = 3 #Repeatable read (*ALL)     --> QSQCLIPKGA
    RR = 4 #Serializable (*RR)          --> QSQCLIPKGL

class ConnectionType:
    ReadWrite = 0 #Read/Write (all SQL statements allowed)
    ReadCall = 1 #Read/Call (SELECT and CALL statements allowed)
    Readonly = 2 #Read-only (SELECT statements only)

def connstr(system, commitmode=None, connectiontype=None):
    _connstr =  'DRIVER=iSeries Access ODBC Driver;'+\
                'SYSTEM='+system+';'+\
                'SIGNON=4;CCSID=1208;TRANSLATE=1;'
    if commitmode is not None:
        _connstr = _connstr + 'CommitMode=' + str(commitmode) + ';'
    if connectiontype is not None:
        _connstr = _connstr +'ConnectionType=' + str(connectiontype) + ';'

    return _connstr

def main():
    with pyodbc.connect(connstr("SYSTEM",CommitMode.CHG,ConnectionType.Readonly)) as db:
        cursor = db.cursor()
        cursor.execute(
            """
            SELECT * FROM IASP.LIB.FILE
            """)
        for row in cursor:
            print(' '.join(map(str,row)))

if __name__ == '__main__':
    main()