I would like to know more about dunders

[Larz60+]

Ichabod801,

I use dunders quite a bit, but sometimes not sure which ones I need to provide.
For example. in the following code that I wrote, I wasn't sure if I needed to raise StopIteration or not, or if I needed
to include __repr__ Snippsat didn't think I did when I first posted this (pyforum.io):

from collections import namedtuple
import json


class Record:
    def __init__(self, fname=None):
        self.rec = self.read_data_file(fname)
        self.maxitem = len(self.rec)

    def read_data_file(self, fname):
        with open(fname, 'r') as f:
            j = f.read()
        return json.loads(j, object_hook=lambda data: namedtuple('data', data.keys())(*data.values()))

    def __repr__(self):
        return self

    def __iter__(self):
        self.itemnum = 0
        return self

    def __next__(self):
        if self.itemnum > self.maxitem:
            raise StopIteration
        rec = self.rec[self.itemnum]
        self.itemnum += 1
        return rec


if __name__ == '__main__':
    fname = 'StockData.json'
    r = Record(fname)
    for record in r:
        print(record)

There's a pretty good write up in the Fluent Python book which I have been reading, need to read more, so I
will just absorb what comes along. I usually learn at least something new from all that I read.

I took a quick look at your post, and it looks very interesting, I'll read it tomorrow morning as that's when my brain works best. Getting old sucks!

Larz60+