Question

I was wondering if there was a way to run a command line executable in python, but pass it the argument values from memory, without having to write the memory data into a temporary file on disk. From what I have seen, it seems to that the subprocess.Popen(args) is the preferred way to run programs from inside python scripts.

For example, I have a pdf file in memory. I want to convert it to text using the commandline function pdftotext which is present in most linux distros. But I would prefer not to write the in-memory pdf file to a temporary file on disk.

pdfInMemory = myPdfReader.read()
convertedText = subprocess.<method>(['pdftotext', ??]) <- what is the value of ??

what is the method I should call and how should I pipe in memory data into its first input and pipe its output back to another variable in memory?

I am guessing there are other pdf modules that can do the conversion in memory and information about those modules would be helpful. But for future reference, I am also interested about how to pipe input and output to the commandline from inside python.

Any help would be much appreciated.

Answer 1

with Popen.communicate:

import subprocess
out, err = subprocess.Popen(["pdftotext", "-", "-"], stdout=subprocess.PIPE).communicate(pdf_data)