IsADirectoryError: [Errno 21] Is a directory: '/' while copying files from one folder to another existing folder Python

Question

I'm making a basic file manager to practice. I've ran into trouble while trying to copy files from a directory, into another already existing directory.

def singulateDataInDir(SRCdir, passBackFiles=bool, passBackDirs=bool):
    for root, dirs, files in os.walk(SRCdir, topdown=True):
        for name in files:
            filesInSRCdir = os.path.join(root, name)
            if passBackFiles is True:
                return filesInSRCdir
        for name in dirs:
            dirsInSRCdir = os.path.join(root, name)
            if passBackDirs is True:
                return dirsInSRCdir

def copyFilesFromSRCtoDEST(SRCdir, DESTdir):  
    for files in singulateDataInDir(SRCdir, True, False):
        shutil.copy2(files, DESTdir)

I attempt to sort through items in the SRCdir and depending on the parameters it returns files, directories, or both. I get an error saying my destination is a directory (I think? perhaps the '/' means that I'm typing the code incorrectly.)

Traceback (most recent call last):
  File "main.py", line 45, in <module>
    main(True)
  File "main.py", line 38, in main
    code.copyFilesFromSRCtoDEST(srcOpt, destOpt)
  File "/Users/jcrd/Documents/csProjects/pythonProjects/screenshotCollecting/code.py", line 34, in copyFilesFromSRCtoDEST
    shutil.copy2(files, DESTdir)
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.8/lib/python3.8/shutil.py", line 432, in copy2
    copyfile(src, dst, follow_symlinks=follow_symlinks)
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.8/lib/python3.8/shutil.py", line 261, in copyfile
    with open(src, 'rb') as fsrc, open(dst, 'wb') as fdst:
IsADirectoryError: [Errno 21] Is a directory: '/'

Any help would be amazing, thank you for looking at my question.

Answer 1

The problem is that singulateDataInDir does not yield filenames and is not a generator. It returns a single path with return filesInSRCdir and so

for files in singulateDataInDir(SRCdir, True, False):

iterates the characters in the name returned, starting with the leading forward slash "/". Thus the error Is a directory: '/' . Te fix is to yield instead of return . You also need to fiddle with the default parameters to the function. bool is a type object, it doesn't mean that input has to be a bool.

def singulateDataInDir(SRCdir, passBackFiles=False, passBackDirs=False):
    for root, dirs, files in os.walk(SRCdir, topdown=True):
        for name in files:
            filesInSRCdir = os.path.join(root, name)
            if passBackFiles is True:
                yield filesInSRCdir
        for name in dirs:
            dirsInSRCdir = os.path.join(root, name)
            if passBackDirs is True:
                yield dirsInSRCdir

def copyFilesFromSRCtoDEST(SRCdir, DESTdir):  
    for files in singulateDataInDir(SRCdir, True, False):
        shutil.copy2(files, DESTdir)