What's the difference between './' and '../' when using os.path.isdir()?

Question

I'm new to python. And something is confusing me today. Under the path c:\python\, there are several folds. I edit a python script under this path, and run the code:

for dir_name in os.listdir("./"):
        print dir_name
        print os.path.isdir(dir_name)

It prints:

Daily
True
renafile.py
False
script
True

But when I put the script in fold Daily which is under the path C:\python\,and run code:

for dir_name in os.listdir("../"):
        print dir_name
        print os.path.isdir(dir_name)

It prints:

Daily
False
renafile.py
False
script
False

Did they have the difference?

Anish Goyal · Accepted Answer · 2017-03-23T07:33:09.573

9

It was returning false because when you call isdir with a folder name, python looks for that folder in the current directory - unless you provide an absolute path or a relative path.

Since you are listing files in "../", you should call isdir like so:

print os.path.isdir(os.path.join("../", dir_name))

You may want to modify your code to:

list_dir_name = "../"
for dir_name in os.listdir(list_dir_name):
  print dir_name
  print os.path.isdir(os.path.join(list_dir_name, dir_name))

edited Mar 23 '17 at 07:33

answered Mar 23 '17 at 07:29

Anish Goyal

2,799
12
17

2

I would recommend using `os.path.join` instead of just `+`. – shad0w_wa1k3r Mar 23 '17 at 07:31
@AshishNitinPatil good call, I changed the snippet :) L.Bes, glad I could help :) – Anish Goyal Mar 23 '17 at 07:33
1

Anish Goyal - Sorry, I click solved just now and it notice 'in 5 minutes' – L.Bes Mar 23 '17 at 07:47
It's fine haha, I probably shouldn't have mentioned it. Thank you though – Anish Goyal Mar 23 '17 at 07:49
1

Haha, I did that before you mentioned it. Anyway, this is my first question on stackoverflow. Thank you! – L.Bes Mar 23 '17 at 09:15

What's the difference between './' and '../' when using os.path.isdir()?

1 Answers1