Issue with returning custom object type

[ThomasWarenski]

I am working on the Advent of Code challenges, and Day 7 has proven a little difficult. I decide to create a class directory() with properties- or whatever the technical python term is- name, contents, and sum. Name is a name, contents is a list of “files” in the directory, which contains other directories and strings, and sum is unused, but will have a future use. My question is why does line 31 give me TypeError: cannot unpack non-iterable NoneType object

Repl link:

class directory():
	name = ""
	# used to identify the directory
	contents = []
	sum = 0

file = open("input.txt")

moreLines = True

slash = directory()
slash.name = "/"

def readDir(file, dir, line):
	newLine = ""
	for i in line:
		if i != line[0] and i != line[1] and i != line[2] and i != line[3]  and i != line[len(line)-1]:
			newLine += i
	if dir.name == newLine:
		temp = file.readline()
		temp = file.readline()
		if temp[0] == "$":
			return dir, temp
		else:
			slash.contents.append(temp)

line = file.readline()
slash, line = readDir(file,slash,line)```

[IanAtCSTeach]

Hi @ThomasWarenski

You haven’t used classes correctly. I recommend you read up on these by using a site such as W3Schools or the Python website itself.

Python Classes

class directory():
   def __init__(self):
      self.name = ""
      self.contents = []
      self.sum = 0

[ThomasWarenski]

Thank you!
That’s what I was afraid of, I’m still learning, which, I suppose is what replit ask is for.
I actually had read through the W3Schools page previously, but I didn’t really think I understood. Seeing how you would do it in my place has confirmed it to me though, so thank you very much.

[ThomasWarenski]

Could you or someone else verify that my new updated code is correct? I’m still getting the same error.

class directory():
   def __init__(self,nomen):
      self.name = nomen
      self.contents = []
      self.sum = 0

file = open("input.txt")

moreLines = True

slash = directory("/")

def readDir(file, dir, line):
	newLine = ""
	for i in line:
		if i != line[0] and i != line[1] and i != line[2] and i != line[3]  and i != line[len(line)-1]:
			newLine += i
	if dir.name == newLine:
		temp = file.readline()
		temp = file.readline()
		if temp[0] == "$":
			return dir, temp
		else:
			if temp[0] == "d":
				newDir = temp
				slash.contents.append(newDir)
			else:
				slash.contents.append(temp)

line = file.readline()
slash, line = readDir(file,slash,line)

[IanAtCSTeach]

Hi @ThomasWarenski I’m glad the previous reply helped!

When I run your code now I see the following error message:

I tracked the error to line 26 shown below:

If you take out the self parameter it should work. You only refer to self parameters within the class definition, not the rest of the program code. Hope this helps!

[ThomasWarenski]

I think the self was in there because I was having problems with the init() function, as I posted in another topic.
It ended up resolving the issue with init() but caused the above bug apparently.

[IanAtCSTeach]

Hi @ThomasWarenski it would be easier if you kept one topic open for the Repl rather than posting multiple times.

The self should not be used outwith the class definition.

[ThomasWarenski]

Alright, I wasn’t sure because I’ve been on sites where they’re really picky that only one question goes in a topic.

[IanAtCSTeach]

Thanks @ThomasWarenski I understand but it was the same Repl, so easier to keep track asynchronously.