pymysql.err.DataError: (1366, "Incorrect integer value:

Question

Getting this error, while trying to sent information to database via this code in python:

with open('ypatybes_paruosta.csv', encoding='utf-8') as data2:
    csvreader = csv.reader(data2, delimiter = ';')
    next(csvreader)
    for row in csvreader:
        print(row)
        cursor.execute(
                'INSERT INTO flat_features(flat_id, features_id) VALUES (%s, %s)', row)
conn.commit()
cursor.close()

There's only to values, but one of the value (feature_id), have empty value. And for some reason it doesnt like it.
This is what i see in output window before getting mentioned error:

['1', '5']
['2', '5']
['2', '3']
['3', '']

Can someone help with that ? Thanks !

P.S. I saw solution here python mysql script: DataError: (1366, "Incorrect integer value: but it doesnt help in my case

Table creation code in mysql:

CREATE TABLE flat_features(
flat_features_id int NOT NULL AUTO_INCREMENT,
flat_id INT NOT NULL,
features_id INT NOT NULL,
PRIMARY KEY(flat_features_id),
CONSTRAINT fk_flat_features FOREIGN KEY(flat_id) REFERENCES flats(flat_id) ON UPDATE CASCADE, 
CONSTRAINT fk_featuresID FOREIGN KEY(features_id) REFERENCES features(features_id) ON UPDATE CASCADE 
);