def individualize_subprocess_run(run_args, run, to_replace):
    """
    Cycle through every argument in run_args and replace instances of the
    to_replace string with run, then return the arguments.
    :param run_args: List of strings, all arguments to call via subprocess
    :param run: Whole number (as an int or a string) defining which run this is
    :param to_replace: String to find and replace with each run name/id
    :return: run_args, but with to_replace replaced by run in them all
    """
    for i in range(len(run_args)):
        run_args[i] = str(run_args[i]).replace(to_replace, str(run))
    return run_args