CODEWITHSUNDEEP
pythonattributeerror
Mathew Shiju
Mathew Shiju

Reputation: 23

Python: AttributeError: 'str' object has no attribute when calling a method inside for loop

When I try to access the class instance using the name generated by a for loop I am getting

"AttributeError: 'str' object has no attribute".

I am new to Python and please excuse any "Not the best practice". Any help is appreciated

class Csv:
    def __init__(self, invoicenum, customer, invoicedate, duedate, description, amount, productservice, invoiceclass):
        self.invoicenum = invoicenum
        self.customer = customer
        self.invoicedate = invoicedate
        self.duedate = duedate
        self.description = description
        self.amount = amount
        self.productservice = productservice
        self.invoiceclass = invoiceclass
        self.line = '{},{},{},{},{},{},{},{}\n'.format(invoicenum, customer, invoicedate,
                                                       duedate, description, amount, productservice, invoiceclass)

    def wite_to_db(self):
        mydb = mysql.connector.connect(host="localhost", user="root",
                                       passwd="passwd", database="invoice")
        mycursor = mydb.cursor()
        sql = "insert into invoice " "(Invoice_no, Customer, Invoice_Date, Due_date, Description, Amount, Product_service, Class)" "VALUES (%s,%s,%s,%s,%s,%s,%s,%s)"
        val = (self.invoicenum, self.customer, self.invoicedate, self.duedate,
               self.description, self.amount, self.productservice, self.invoiceclass)
        mycursor.execute(sql, val)
        mydb.commit()


x0 = Csv("1355", "Test1 User", "2020-05-03", "2020-12-31", 7095, 300, "Tithe", "General Fund")
x1 = Csv("1124", "Test2 User", "2020-05-03", "2020-12-31", 7095, 300, "Tithe", "General Fund")
x2 = Csv("14432", "Test3 User", "2020-05-03", "2020-12-31", 7095, 300, "Tithe", "General Fund")
x3 = Csv("1312", "Test4 User", "2020-05-03", "2020-12-31", 7095, 300, "Tithe", "General Fund")


line_range = range(4)

for line in line_range:
    line_instance = 'x' + str(line)
    print(line_instance)
    line_instance.write_to_db()

Upvotes: 1

Views: 1517

Answers (4)

Mathew Shiju
Mathew Shiju

Reputation: 23

I assigned the class instances to a list and was able to call the method for the instances looping over it. All ya' are awesome.

Upvotes: 1

Bar Gans
Bar Gans

Reputation: 1653

line_instance is a str. str has no function called write_to_db

Upvotes: 1

Diggy.
Diggy.

Reputation: 6944

What you've done is when you created the line_instance variable, you made it a string, and then a couple lines later you essentially tried to run the function in your Csv class - write_to_db on a string. That's why the error is occuring.

What I can recommend doing is something as follows:

x0 = Csv(...
x1 = Csv(...
x2 = Csv(...
x3 = Csv(...

x_list = [x0, x1, x2, x3]

for x in x_list:
    x.write_to_db()

Sidenote, you have a typo in your definition in the "wite_to_db" function in your Csv class

Upvotes: 1

Błotosmętek
Błotosmętek

Reputation: 12927

line_instance = 'x' + str(line)
print(line_instance)
line_instance.write_to_db()

This is wrong. Strings do not have write_to_db method. You defined this method (or rather a very similarly named wite_to_db…) in your Csv class, but line_instance obviously is a string here, not an instance of Csv class. What you probably wanted to do is:

for line_instance in (x0, x1, x2, x3):
    line_instance.write_to_db()

Upvotes: 2

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