Using Python to create incrementing folder names

Question

I am trying to place all files within a directory into it's own individual folder. When trying to declare the variable 'folders' I enumerate the list of files and try to append the enumerated list number to the end of the folder name, so the folders would look something like... FOLDER_1, FOLDER_2, FOLDER_3, where the trailing digit is generated from enumeration of the files in the directory.

However my code below lists them all as 'FOLDER_0' and then hits an overwrite error, my increment doesn't seem to be working, any direction into what I am doing wrong would be much appreciated.

PATH = "C:/Temp/"

def main(): 
    files = [ join(PATH, f) for f in listdir(PATH) if isfile(join(PATH, f)) ]

    for i, f in enumerate (files):
        folders = [ PATH+"FOLDER_"+str(i)+"/" for f in files ]

What would you like to have in folders after the for-loop? Now you iterate through files but use f nowhere, i.e. the last line is equivalent to folders = [ PATH+"FOLDER_"+str(i)+"/" ] * len(files), which may not be what you want. Also, you are using the variable f twice (outer and inner loop), which really may cause problems. — DrV
– DrV, Commented Jun 16, 2014 at 18:06
Each time you perform the for cycle, a new variable folders is created. You must initialize an empty variable folders = [] before the for cycle and then use the list.append() method or the += operator to add a new item: folders.append([ PATH+"FOLDER_"+str(i)+"/" for f in files ]) — s3n0
– s3n0, Commented Mar 5, 2019 at 13:37
However, I see more discrepancies. Why do you use enumerate if you do not need it? You can also use: for i in range(len(files)) or make a one-line function as for the files variable: folders = [ PATH+"FOLDER_"+str(i)+"/" for i in range(len(files)) ] — s3n0
– s3n0, Commented Mar 5, 2019 at 13:53

Community · Accepted Answer · 2017-05-23 11:52:58Z

1

It is not really clear what your end goal is, but from what you have shown in your code and written in your question I think I can take a stab at it.

To start python uses zero based indexing, so the first value corresponding to the first item in enumerate will be 0.
Next your for loop is equivalent to doing something like this:

folders = [PATH + "FOLDER_" + str(len(files))] * len(files)

So for...

files=["file1", "file2"]

you would get...

folders=["FOLDER_1", "FOLDER_1"]

This is likely where the "overwrite error" is indirectly coming form. If you tried to create every folder in folders you get an OSError telling you that you are creating a folder you just created.

If you wanted to create a folder for each file you had in a directory, I would try to modify your code into this direction:

PATH = "C:/Temp/"

def main():
    files = [join(PATH, f) for f in listdir(PATH) if isfile(join(PATH, f))]
    folders = [join(PATH, "FOLDER_{}".format(i + 1)) for i, _ in enumerate(files)]
    ...

And then if you are going to create all the folders in folders check they don't already exist

edited May 23, 2017 at 11:52

CommunityBot

11 silver badge

answered Jun 16, 2014 at 18:29

MrAlias

1,36615 silver badges28 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

MikG Over a year ago

Thank you so much MrAlias, your solution is exactly what I was looking for, and much more efficient than my original method. Cheers!

Collectives™ on Stack Overflow

Using Python to create incrementing folder names

1 Answer 1

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related