AttributeError: 'str' object has no attribute 'file_name'

csvdb.py

import csv

class open():
    def __init__(self, file):
        self.file_name = file
    
    
    def rows(self):

        field= []
        rows = []
        with open(self.file_name,encoding='utf-8')as r_file:
            csvreader = csv.reader(r_file)
            fields = next(csvreader)

            for row in csvreader:
                rows.append(row)

            return rows
    def field(self):

        field= []
        rows = []
        with open(self.file_name,encoding='utf-8')as r_file:
            csvreader = csv.reader(r_file)
            fields = next(csvreader)

            for row in csvreader:
                rows.append(row)

            return fields

main.py

import csvbd


fields = csvbd.open.field('main.csv')

print(fields)

Python 3.12

Столкнулся с проблемой.

Выводит в терминал:

Traceback (most recent call last):
  File "c:\Users\Admin\Documents\TESTDBSVC\testapi.py", line 4, in <module>
    fields = csvbd.open.field('main.csv')
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\Admin\Documents\TESTDBSVC\csvbd.py", line 29, in field
    with open(self.file_name,encoding='utf-8')as r_file:
              ^^^^^^^^^^^^^^
AttributeError: 'str' object has no attribute 'file_name'

Вроде init я сделал правильно, но он все равно жалуется на то, что нет атрибута file_name