Escaping the result of a subquery in sql insert statements for pandas

I'm importing a csv on MariaDB using python & pandas,the isert statements need a couple of subqueries, here is the code:

empdata = pd.read_csv(
    "static/files/testfile.csv",
    index_col=False, delimiter=";", on_bad_lines="skip"
)


if conn.is_connected():
    cursor = conn.cursor()
    cursor.execute("select database();")
    record = cursor.fetchone()
    # print (record)
    print("You're connected to database: ", record)
    # loop through the data frame
    for i, row in empdata.iterrows():
        # print(row)
        # here %S means string values
        sql = "INSERT INTO PRODOTTI (PROD_ATTIVO,EAN13,prod_nome,Prezzo,CAT_IVA_idCAT_IVA,Costo,Quantita,Fornitori_idFornitori,Data_ins) \
                VALUES (%s,%s,%s,%s,(select idCAT_IVA from CAT_IVA where CAT_IVA_aliquota = %s),%s,%s,(select idFornitori from Fornitori where Fornitori_nome = %s),%s)"

and all works fine until one of the answer of a subuery contains a space than I got this error:

(1, '3649833526', 'Example product', 15.9, 0.22, '8.94', '2', 'example dealer', '2021/01/02')
Error while inserting in DB 1048 (23000): Column 'Fornitori_idFornitori' cannot be null

It seems to me that the subqueries search just for 'example' and not for 'example dealer' so it get a NULL answer, and I haven't found a way to escape this field and avoid this behaviour.

Some one knows how to solve this issue?

Thank you.

I've tried different csv encoding and escaping in the query but without result.

As you defined Fornitori_idFornitori as NOT NULL you need to provide a value for the column, as 0 isn't part if an auto_increment you can use it or -1

sql = "INSERT INTO PRODOTTI (PROD_ATTIVO,EAN13,prod_nome,Prezzo,CAT_IVA_idCAT_IVA,Costo,Quantita,Fornitori_idFornitori,Data_ins) \
VALUES (%s,%s,%s,%s,COALESCE((select idCAT_IVA from CAT_IVA where CAT_IVA_aliquota = %s),0),%s,%s,COALESCE((select idFornitori from Fornitori where Fornitori_nome = REPLACE(%s, ' ','')),0),%s)"