Tidy up whois, add docstring

Author: dmptrluke

plugins/whois.py

@@ -1,6 +1,10 @@
-from contextlib import suppress
+"""
+whois.py
+Provides a command to allow users to look up information on domain names.
+"""
 
 import pythonwhois
+from contextlib import suppress
 
 from cloudbot import hook
 
@@ -10,9 +14,13 @@ def whois(text):
     """<domain> -- Does a whois query on <domain>."""
     domain = text.strip().lower()
 
-    data = pythonwhois.get_whois(domain, normalized=True)
+    try:
+        data = pythonwhois.get_whois(domain, normalized=True)
+    except pythonwhois.shared.WhoisException:
+        return "Invalid input."
     info = []
 
+    # We suppress errors here because different domains provide different data fields
     with suppress(KeyError):
         info.append("\x02Registrar\x02: {}".format(data["registrar"][0]))