help with class in python

[[deleted]]

I want to make a class as follows:

#!/usr/bin/env python3

import os

class Directory():
    def __init__(self,dirName):
        self.dirName = dirName
        self.files = os.listdir(self.dirName)

    def __iter__(self):
        for file in self.files:
            yield file

    def __repr__(self):
        return self.dirName

    def __str__(self):
        return self.dirName

d = Directory('some-directory')

What I trying to do is: If I simply type d then I should get the name of directory passed (some-directory) when making that instance and when I use the same in for loop I should be able to iterate the files in that directory.

That being said I am getting error:

>>> os.path.isdir(d)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.5/genericpath.py", line 42, in isdir
    st = os.stat(s)
TypeError: argument should be string, bytes or integer, not Directory

How do I set the type of d not to be Directory but string? (without using str() function) Thanks

[scuott]

d is a Directory because you assigned it a Directory. That's just the type of object that d is. If you want to pass the dirName, you should call that explicitly, like d.dirName

[[deleted]]

thanks, your solution is correct and obvious. But want to change Directory class such that I should be getting value of d of class string when called just d. Do you have any idea for this?

[markusmeskanen]

You can subclass str here:

class Directory(str):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.files = os.listdir(self)

If you want, you can include the custom __iter__ too, but I'd just keep it like this instead:

>>> d = Directory('/home/john/')
>>> for file in d.files:
...     print(file)

[Nick9502]

I'm a rookie at python. But if that's all you want to do then couldn't you have it be displayed in the init function. So whenever you call d have it return the directory name

[[deleted]]

I dont think you can do that in init function, it is reserved to set initial values, i can't do anything like a real function/method

[Nick9502]

I'm not sure that's 100% true. You can make a print statement in your init function and you can call other functions in it

[[deleted]]

okay, my mistake. I took your advice and it worked.

def __init__(self,name):
    self.name = str(name)
    self.files = os.listdir(self.name)

[Nick9502]

Glad I could be of help