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Python Regular Expressions in Python Introduction to Regular Expressions Players Dictionary and Class

Posted by Denis Chernenko
Denis Chernenko
4,077 Points

my Class + regular expressions is not working together

I expect to provide class 3 positional arguments, but have an error: TypeError: init() takes 1 positional argument but 2 were given

Please advice what need to be done correctly

import re

string = '''Love, Kenneth: 20
Chalkley, Andrew: 25
McFarland, Dave: 10
Kesten, Joy: 22
Stewart Pinchback, Pinckney Benton: 18'''

players_compiled = re.compile(r"""
^(?P<last_name>[\w ]*)
,\s
(?P<first_name>[\w ]*)
:\s
(?P<score>[\d]*)$
""", re.X|re.M)

class Player:
    def __init__(self, **kwargs):
        for key, value in kwargs.items():
            if key == "first_name":
                self.first_name = value
            elif key == "last_name":
                self.last_name = value
            elif key == "score":
                self.score = value

something = Player(players_compiled.finditer(string))
print (something)

2 Answers

Greg Kaleka
Greg Kaleka
39,021 Points
Greg Kaleka
Greg Kaleka
39,021 Points

Hi Denis,

I think you're over-thinking this a bit. You don't need to dynamically set the Player's attributes - you know what they will be. A simple init statement is all you need. It should accept last_name, first_name and score as arguments.

I see what you're trying to do, which is pretty clever, although as your code is written, you're just passing an iterable object to init, which is why you're getting that error. You haven't passed any kwargs. Jump into a python shell to prove this to yourself.

>>> players_compiled.finditer(string)
<callable-iterator object at 0x10e4dd410>

Again, there's no reason not to set the arguments explicitly in your init, but if you did want to just accept **kwargs, you would need a for loop and groupdict(). If you want a little project, go back to the previous video and see if you can figure out how to create instances of Player rather than printing the dictionary. Hint - you'll need to use ** on the dictionary...

Let me know if this all makes sense!

Cheers :beers:

-Greg

solution.py 
class Player:
    def __init__(self, last_name, first_name, score):
        self.last_name = last_name
        self.first_name = first_name
        self.score = score
Denis Chernenko
Denis Chernenko
4,077 Points
Denis Chernenko
Denis Chernenko
4,077 Points

Hi Greg,

Thank you for explanation. Actually i've passed exam but i want to understand how classes + regular expressions can work together with multiple number of arguments like it happens in real life :)

I would really appreciate other code example if it possible to use class to get some data(tuple, dictionary) from imported file.