Python - Define class with one method and one attribute

I'm new to Python and trying create a program that defines a class called person that has one method called hello, and one attribute called name, which represents the name of the person. The hello method should print the following string to the screen:

‘My name is name attribute and I am a name of class’

1)Instantiate an object of the class, 2)Run the hello method of the instantiated object (e.g., John.hello()), 3) Use sys.argv

Here is my code:

import sys

class person():
    def __init__(self,_name):
        self.name=_name
        _name = sys.argv[1]
    def hello(self):
        print (f"My name is {sys.argv[1]} I am a {self.__class__.__name__}")

p1 = person()
p1.hello()

def main():
    p = person()
    print (type(p))

if __name__ == "__main__":
    main()

Example expected output:

My name is Obi-Wan and I am a person
<class '__main__.person'>

Actual output:

  File "classname.py", line 10, in <module>
    p1 = person()
TypeError: __init__() missing 1 required positional argument: '_name'

I don't know what I am doing wrong. Please help!