CODEWITHSUNDEEP
python
GoGo
GoGo

Reputation: 639

TypeError: list() takes at most 1 argument (3 given) for list class inheritance

I searched other posts in stackoverflow and even copied them to try on my machine as answered. However, it keep failing throwing "TypeError"

# this is as one of other post in StackOverflow. 
class ListClass(list):
    def __init__(self, *args):
        super().__init__(self, *args)
        self.append('a')
        self.name = 'test'

I also tried empty class with pass. But, that also fails if I inherit and I guess I missed something instead of adding something more or wrong?

1) what is this "TypeError" and why? 2) how to fix it?

further snapshot on TypeError:

>>> class ListClass(list):
...     pass
...
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: list() takes at most 1 argument (3 given)

Upvotes: 4

Views: 14368

Answers (2)

Moses Koledoye
Moses Koledoye

Reputation: 78546

Pass the tuple of arguments args to your instance's extend:

>>> class ListClass(list):
...     def __init__(self, *args):
...         super().__init__()
...         self.extend(args)
...         self.append('a')
...         self.name = 'test'
...
>>> ListClass(1, 2, 3)
[1, 2, 3, 'a']

Or pass the unpacked tuple of args to super's __init__ since list can be initialized with an iterable

>>> class ListClass(list):
...     def __init__(self, *args):
...         super().__init__(args) # one argument: tuple
...         self.append('a')
...         self.name = 'test'
...
>>> ListClass(1, 2, 3)
[1, 2, 3, 'a']

Update:

What you've probably done is assigning an object to the name list:

>>> list = []
>>> class ListClass(list):
...    pass
...
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: list() takes at most 1 argument (3 given)

Upvotes: 3

wind85
wind85

Reputation: 487

You are giving it to many paramerters when you create the ListClass object, this is what you are doing:

s = list(2,3,3)

This is what you shuold be doing:

s = list([2,3,3])

Try this snippets on you interpreter.

Upvotes: 6

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