I have a script in Python (Windows 10) whose one of the functions is supposed to create a backup. Here’s the function:

def create_backups(self, file: str, counter: int = None) -> None:
    counter = counter or 1
    res = self.re_obj.match(file)
    if res is None or len(res.groups()) == 0:
        back_file = f"{file} ({counter}).{self.ext}"
    else:
        l_res = re.search("\w[\w\s]+?\.[a-zA-Z_]\w{2}", file)
        file_name, file_ext = splitext(l_res.group())
        back_file = f"{file_name}{file_ext} ({counter}).{self.ext}"
    if exists(back_file) and counter < self.n_copies:
        counter += 1
        self.create_backups(back_file, counter)
    with open(file, "rb") as f_src, open(back_file, "wb") as f_dst:
        shutil.copy2(f_src, f_dst)
    if self.verbose:
        print(f"Copied {file} to '{back_file}'")

It’s supposed to make several copies (parametrised). As you can see it invokes itself in case the back_file already exists. The pattern is following:

test.txt
test.txt (1).sav
test.txt (2).sav
...
test.txt (n).sav

with n depending on the parameter n_copies.

If I convert it to a exe file, it still works in PowerShell. However, if I try to run it from another program, it raises PermissionError exception on the second copy test.txt (1).sav. For instance, I use FreeCommander XE and I am trying to run the script as follows:

The parameters are following:

• -f file name and FreeCommander subsitutes %ActivSel% with the selection
• -n no. of copies
• -e extension, e.g. sav
• -b backup method

If I run an equivalent parametrised script from PowerShell:

backup.exe -f "test.txt" -n 14 -e "sav"

everything works. It is in the FreeCommander where I’ve got PermissionError exactly at the line of

shutil.copy2(f_src, f_dst)

I also tried to run FreeCommander as administrator with no difference.

I am not sure how to sort this out. Any ideas?