CODEWITHSUNDEEP
pythonflask
Sergio Bost
Sergio Bost

Reputation: 3209

Get method throwing an error, no idea why

I'm getting the error : TypeError: __init__() missing 1 required positional argument

The entire error is:

    [2021-09-04 22:00:53,162] ERROR in app: Exception on /entry/title [GET]
Traceback (most recent call last):

  File "/Users/shakur/PycharmProjects/flaskProject2/venv/lib/python3.9/site-packages/flask/app.py", line 1513, in full_dispatch_request
    rv = self.dispatch_request()

  File "/Users/shakur/PycharmProjects/flaskProject2/venv/lib/python3.9/site-packages/flask/app.py", line 1499, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**req.view_args)

  File "/Users/shakur/PycharmProjects/flaskProject2/venv/lib/python3.9/site-packages/flask_restful/__init__.py", line 467, in wrapper
    resp = resource(*args, **kwargs)

  File "/Users/shakur/PycharmProjects/flaskProject2/venv/lib/python3.9/site-packages/flask/views.py", line 82, in view
    self = view.view_class(*class_args, **class_kwargs)  # type: ignore

TypeError: __init__() missing 1 required positional argument: 'title'
127.0.0.1 - - [04/Sep/2021 22:00:53] "GET /entry/title HTTP/1.1" 500 -

For some reason the get request is throwing an error, I'm at a loss on why... no idea. Any suggestions would be appreciated

from flask import Flask
from flask_restful import Resource, Api
import sqlite3

app = Flask(__name__)
app.secret_key = "xyz"
api = Api(app)

class Entry(Resource):

    def __init__(self, title, language="Python", attempts=0,wins=0):
        self.title = title
        self.language = language
        self.attempts = attempts
        self.wins = wins


    def __repr__(self):
        #...


    def record_attempts_and_wins(self, a, w=0):
        #...

    @classmethod
    def find_entry_by_title(cls, title):
        connection = sqlite3.connect("data.db")
        cursor = connection.cursor()

        query = "SELECT * FROM entries WHERE title=?"
        result = cursor.execute(query, (title,))
        column = result.fetchone()
        if column:
            entry = cls(*column)
        else:
            entry = None

        connection.close()
        return entry


    def get(self, title):
        entry = Entry.find_entry_by_title(self, title)
        return entry

api.add_resource(Entry, "/entry/<string:title>")

Upvotes: 0

Views: 571

Answers (1)

Mark
Mark

Reputation: 92440

Flask doesn't know that you have added positional arguments to the Resource subclass. When you call:

api.add_resource(Entry, "/entry/<string:title>")

it just thinks Entry will be a Resource, which doesn't have a title argument in its constructor. How could it know it needs to pass a title when it calls the Entry() constructor?

This is addressed in the docs for passing constructor parameters into resources. You need to tell it what to pass as a title:

api.add_resource(Entry, "/entry/<string:title>", resource_class_kwargs={ 'title': "some title" })

Upvotes: 5

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