Implement lazy-importing of oursql and pytz.

earwigbot/commands/time_command.py

@@ -24,10 +24,11 @@ from datetime import datetime
 from math import floor
 from time import time
 
-import pytz
-
+from earwigbot import importer
 from earwigbot.commands import Command
 
+pytz = importer.new("pytz")
+
 class Time(Command):
     """Report the current time in any timezone (UTC default), or in beats."""
     name = "time"
@@ -52,12 +53,12 @@ class Time(Command):
         self.reply(data, "@{0:0>3}".format(beats))
 
     def do_time(self, data, timezone):
-        if not pytz:
+        try:
+            tzinfo = pytz.timezone(timezone)
+        except ImportError:
             msg = "This command requires the 'pytz' module: http://pytz.sourceforge.net/"
             self.reply(data, msg)
             return
-        try:
-            tzinfo = pytz.timezone(timezone)
         except pytz.exceptions.UnknownTimeZoneError:
             self.reply(data, "Unknown timezone: {0}.".format(timezone))
             return

earwigbot/wiki/site.py

@@ -32,14 +32,14 @@ from urllib import quote_plus, unquote_plus
 from urllib2 import build_opener, HTTPCookieProcessor, URLError
 from urlparse import urlparse
 
-import oursql
-
-from earwigbot import exceptions
+from earwigbot import exceptions, importer
 from earwigbot.wiki import constants
 from earwigbot.wiki.category import Category
 from earwigbot.wiki.page import Page
 from earwigbot.wiki.user import User
 
+oursql = importer.new("oursql")
+
 __all__ = ["Site"]
 
 class Site(object):
@@ -514,10 +514,6 @@ class Site(object):
         may raise its own exceptions (e.g. oursql.InterfaceError) if it cannot
         establish a connection.
         """
-        if not oursql:
-            e = "Module 'oursql' is required for SQL queries."
-            raise exceptions.SQLError(e)
-
         args = self._sql_data
         for key, value in kwargs.iteritems():
             args[key] = value
@@ -531,7 +527,11 @@ class Site(object):
         if "autoreconnect" not in args:
             args["autoreconnect"] = True
 
-        self._sql_conn = oursql.connect(**args)
+        try:
+            self._sql_conn = oursql.connect(**args)
+        except ImportError:
+            e = "Module 'oursql' is required for SQL queries."
+            raise exceptions.SQLError(e)
 
     def _get_service_order(self):
         """Return a preferred order for using services (e.g. the API and SQL).