I'm trying to change a lot of pdf-files. Because of this I must open a lot of files. I use the method open to many times. So python gives the error ***too many open files***. 

I hope my code is grace.writer many too similar 

```
readerbanner = PyPDF2.pdf.PdfFileReader(open('transafe.pdf', 'rb'))
readertestpages = PyPDF2.pdf.PdfFileReader(open(os.path.join(Cache_path, cache_file_name), 'rb'))
writeroutput.write(open(os.path.join(Output_path,cache_file_name), 'wb'))

or

writer_output.write(open(os.path.join(Cache_path, str(NumPage) + "_" + pdf_file_name), 'wb'))
reader_page_x = PyPDF2.pdf.PdfFileReader(open(os.path.join(PDF_path, pdf_file_name), 'rb'))

```

All the open methods do not use ***f\_name = open("path","r")***.

because all open file have period. I know the position but not know how close all open files.