Format dates for use with Progress Database from Pyhton

I run an order import routine and I am modify a python script to check that they are in the system once it is done importing.  My code lookeds like this.  I am trying to learn the pieces of putting this together.  If I take the date part out I can get it to return orders to the screen so I know it is a formatting issue on the date that is making this not work correctly. I am using the pyodbc library.

d = datetime.datetime(2017, 5, 3)
print (d)
sql = "select OrderNum, POnum, OrderDate from PUB.OrderHed where OrderDate ="+d
cnxn = pyodbc.connect("DRIVER={Progress OpenEdge 10.1b Driver};HostName="+host+";DATABASENAME="+database+";PORTNUMBER="+port+";LogonID="+login+";PASSWORD="+password)
cursor = cnxn.cursor()
cursor.execute(sql)
rows = cursor.fetchall()
for row in rows:
    print(row.OrderNum, row.PONum, row.OrderDate)

this is what it returns.

    sql = "select OrderNum, POnum, OrderDate from PUB.OrderHed where OrderDate ="+d

TypeError: must be str, not datetime.datetime

I have tried everything I can find to convert to a string but then I am not sure that if it is a string format trying to pull a datetime format from progress if that is the error.

Any help would be greatly apppreciated.