Show error message elegantly

ungleich_pay.py

@@ -1,5 +1,6 @@
 import urllib.request
 import json
+import sys
 from pyotp import TOTP
 
 UNGLEICH_PAY_SERVER_URL = "https://pay.ungleich.ch"
@@ -45,6 +46,13 @@ class ungleichPay(object):
                                          "token": TOTP(args.seed).now(),
                                          "Accept": "application/json"
                                      })
-        response = urllib.request.urlopen(req)
+        try:
+            response = urllib.request.urlopen(req)
+        except urllib.error.HTTPError as err:
+            print(str(err))
+            sys.exit(1)
+        except urllib.error.URLError as uerr:
+            print(str(uerr))
+            sys.exit(2)
         response_json = json.loads(response.read().decode('utf-8'))
         print(response_json["data"])