Multithreaded python script calls the COMMAND LINE
 

I python script does ftp download in a multi threaded way. Each thread downloads a file, close the file, calls the comman line to convert the .doc to pdf. Command line should go ahead and convert the file. My question is, when each thread calls the command line, does one command line process all the request, or each thread creates a one command line process and executes the command? For some reason I am getting "File '1' is alread exists, Do you want to overwrite [y/n]?" I have to manually enter 'y' or 'n' for the script to complete

How do you call the command-line app, and what version of Python are you using?