Click on the Raw button on the script page to get the actual script file, then use File > Save As.. to save the script. Do not use right click > Save As.. on the script link as this will save the HTML ...
$ ./ApacheTomcatScanner.py -h Apache Tomcat Scanner v3.4 - by Remi GASCOU (Podalirius) usage: ApacheTomcatScanner.py [-h] [-v] [--debug] [-C] [--show-cves ...