distutils is replaced with shutil since the former is deprecated in P…

…ython 3.12

README.md

@@ -7,7 +7,7 @@ Project homepage: https://github.com/kbat/mc-tools
 * Emacs [syntax highlighting script](https://github.com/kbat/mc-tools/blob/master/mctools/fluka/fluka-mode.el) for [FLUKA](http://www.fluka.org).
 * [fluka2root](https://github.com/kbat/mc-tools/blob/master/mctools/fluka/fluka2root.py) tool to convert the FLUKA binary output into [ROOT](https://root.cern). It calls the standard FLUKA tools to merge data files and converts the merged files into a single ROOT file. To understand how it works, run the standard example ```$FLUPRO/flutil/rfluka $FLUPRO/exmixed.inp``` and then execute ```fluka2root exmixed.inp```.
   * A more detailed tutorial is available in the [wiki section](https://github.com/kbat/mc-tools/wiki/FLUKA).
-  * Internally, `fluka2root` uses the following convertes which can be called individually:
+  * Internally, `fluka2root` runs the following convertes which can (but should not) be called individually:
     * [usbsuw2root](https://github.com/kbat/mc-tools/blob/master/mctools/fluka/usbsuw2root.py) script to convert the USRBIN results into a TH3F histogram. Note that this tool does not directly convert the files produced by the USRBIN card, but these files must first be averaged by the $FLUPRO/flutil/usbsuw program. The resulting averaged file can be converted into ROOT by ```usbsuw2root```. The $FLUPRO/flutil/usbsuw call is done automatically if the [fluka2root](https://github.com/kbat/mc-tools/blob/master/mctools/fluka/fluka2root.py) general converter is used.
     * [usxsuw2root](https://github.com/kbat/mc-tools/blob/master/mctools/fluka/usxsuw2root.py) script to convert the USRBDX results into a TH2F histogram. + see the comments for the previous item.
     * [usrsuw2root](https://github.com/kbat/mc-tools/blob/master/mctools/fluka/usrsuw2root.py) script to convertert the

mctools/fluka/fluka2root.py

@@ -5,7 +5,7 @@
 import sys, re, os, argparse
 import glob
 from tempfile import NamedTemporaryFile
-from distutils.spawn import find_executable
+from shutil import which
 
 def str2int(s):
     try:
@@ -53,7 +53,7 @@ def __init__(self, args):
         self.verbose    = args.verbose
         self.keep       = args.keep
         self.clean      = args.clean
-        self.parallel   = find_executable("parallel") is not None
+        self.parallel   = which("parallel") is not None
         self.estimators = [Estimator("USRBDX",   "usxsuw"),
                            Estimator("USRBIN",   "usbsuw"),
                            Estimator("USRCOLL",  "ustsuw"),