code: def pdf_merge(inputs: [str], output: str, delete: bool = False):
      
      writer = PdfFileWriter()
      if os.path.isfile(output):
          ans = input(
              "The file '%s' already exists. "
              "Overwrite? Yes/Abort [Y/a]: " % output
          ).lower()
          if ans == "a":
              return
  
      outputfile = open(output, "wb")
      try:
          infiles = []
          for filename in inputs:
              f = open(filename, "rb")
              reader = PdfFileReader(f)
              for page in reader.pages:
                  writer.addPage(page)
              infiles.append(f)
          writer.write(outputfile)
      except FileNotFoundError as e:
          print(e.strerror + ": " + e.filename)
      finally:
          outputfile.close()
          for f in infiles:
              f.close()
      if delete:
          for filename in inputs:
              os.remove(filename)
docs: Merge multiple Pdf input files in one output file.
      :param inputs: input files
      :param output: output file
      :param delete: delete input files after completion if true