Error while copying files in Python from one folder to another

I want to copy my receipts based on the text in PDF. The copy function doesn't work and gives the following error. FileNotFoundError: [Errno 2] No such file or directory

Though it prints the list of files and it is there.

************************** CODE ************************

    #//set path 
    ls_base = r"D:\OneDrive\Documents\Receipts" 
    ls_t1 = r"D:\OneDrive\Documents\Receipts\Org1"
    ls_t2 = r"D:\OneDrive\Documents\Receipts\Org2"
    os.chdir(ls_base)

    files = os.listdir(ls_base)
    print(files) #PRINTS THE LIST OF FILES CORRECTLY


    os.chdir(ls_base)

    for files in os.listdir(ls_base):
        if files.endswith(".pdf"):
            pdfFileObj = open(files, 'rb')
            pdfReader = PyPDF2.PdfReader(pdfFileObj)
            pageObj = pdfReader.pages[0]
            ls_name = re.findall(r'The Paint Shop', pageObj.extract_text())
            pdfFileObj.close()
            ls_file = ls_base + files //get complete file name
            
            if ls_name:
                print(ls_name, pageObj.extract_text().split('Items')[1].split('\n')[1], files)
            
                ls_target = ls_t1 + files
          
                shutil.copy2(ls_file, ls_target)
    
            else:
                #//copy the file to the location "D:\OneDrive\Documents\Receipt\Org2"
                ls_target = ls_t2 + files
                shutil.copy2(ls_file, ls_target)

I think there's "/" missing between ls_base and files in this line:

ls_file = ls_base + files //get complete file name

So ls_file ends up being equal to "D:\OneDrive\Documents\ReceiptsYOUR_PDF.pdf"

In general it helps to print out the names to see if you're getting what is expected.