Adding function "print_running_Python_versions()" for ERROR type exits.

OscScreenGrabLAN.py

 elif sys.argv[1].lower() not in ["png", "bmp", "csv"]:
     print_help()
     print "This file type is not supported: ", sys.argv[1]
+    print
+    print_running_Python_versions()
     sys.exit("ERROR")
 
 file_format = sys.argv[1].lower()
     print instrument_id
     print "Check the oscilloscope settings."
     print "Utility -> IO Setting -> RemoteIO -> LAN must be ON"
+    print
+    print_running_Python_versions()
     sys.exit("ERROR")
 
 # Check if instrument is indeed a Rigol DS1000Z series
         (id_fields[model][:3] != "DS1") or (id_fields[model][-1] != "Z"):
     print
     print "ERROR: No Rigol from series DS1000Z found at ", IP_DS1104Z
+    print
+    print_running_Python_versions()
     sys.exit("ERROR")
 
 print "Instrument ID:",
             if stop_point == 0:
                 data_available = False
                 print "ERROR: Stop data point index lower then start data point index"
+                print
+                print_running_Python_versions()
                 sys.exit("ERROR")
             elif stop_point < n1:
                 break

Rigol_functions.py

 __author__ = 'RoGeorge'
 
 import time
+import pip
+import sys
+
+
+def print_running_Python_versions():
+    print "Running Python version:"
+    print (sys.version)  # parentheses necessary in python 3.
+    print sys.version_info
+    print
+
+    installed_packages = pip.get_installed_distributions()
+    installed_packages_list = sorted(["%s==%s" % (i.key, i.version) for i in installed_packages])
+    print "Installed Python modules:"
+    print(installed_packages_list)
+    print
 
 
 def get_memory_depth(tn):