python - Missing 1 required positional argument (object created and dictionary initialized) -

i see question has been asked before in different variations, feel though have implemented feedback have seen in threads (mainly making sure object created have done in second last night, , making sure dictionary initiated, feel have done in third line) , still receiving error. advice appreciated. thank you!

class groceries:  def __init__(self, grocery_list):     self.grocery_list = {}  def add_item(self, item):     item = input("name: ")     purchased = input(false)     self.grocery_list[item] = purchased  = groceries() something.add_item() 

the error is:

traceback (most recent call last):   file "intermediate_python.py", line 14, in <module>     = groceries() typeerror: __init__() missing 1 required positional argument: 'grocery_list' 

i tried resolve error removing grocery_list def init statement (not sure why work, playing around) , error moved next line with:

traceback (most recent call last):   file "intermediate_python.py", line 15, in <module>     something.add_item()  typeerror: add_item() missing 1 required positional argument: 'item' 

to initialise instance of groceries class need provide parameter "grocery_list" defined in init method

class groceries:     def __init__(self, grocery_list):         self.grocery_list = {} 

try create instance using following:

something = groceries({"milk": 1, "butter": 1}) 

alternatively, allow empty groceries objects, can add default parameter init method, should assigning value of parameter variable self.grocery_list instead of assigning empty dictionary:

class groceries:     def __init__(self, grocery_list={}):         self.grocery_list = grocery_list 

and method add_item, again need pass parameter or else removed parameter (since you're asking input)

def add_item(self):     item = input("name: ")     purchased = input("amount: ")     self.grocery_list[item] = purchased   = groceries({"milk": 0}) something.add_item() >> name: >>> milk >> amount: >>> 1