changed the default value of extra_params argument in the _default_params methods to None from {}

lastfm/api.py

@@ -686,7 +686,8 @@ import urlparse
 
 from lastfm.album import Album
 from lastfm.artist import Artist
-from lastfm.error import error_map, LastfmError, OperationFailedError, AuthenticationFailedError
+from lastfm.error import error_map, LastfmError, OperationFailedError, AuthenticationFailedError,\
+    InvalidParametersError
 from lastfm.event import Event
 from lastfm.filecache import FileCache
 from lastfm.geo import Location, Country

lastfm/artist.py

@@ -369,11 +369,12 @@ class Artist(LastfmBase, Cacheable, Sharable, Shoutable, Searchable, Taggable):
         a._fill_info()
         return a
 
-    def _default_params(self, extra_params = {}):
+    def _default_params(self, extra_params = None):
         if not self.name:
             raise InvalidParametersError("artist has to be provided.")
         params = {'artist': self.name}
-        params.update(extra_params)
+        if extra_params is not None:
+            params.update(extra_params)
         return params
 
     @staticmethod

lastfm/base.py

@@ -8,9 +8,15 @@ __package__ = "lastfm"
 
 class LastfmBase(object):
     """Base class for all the classes in this package"""
+    
+    def __eq__(self, other):
+        raise NotImplementedError("The subclass must override this method")
+    
+    def __lt__(self, other):
+        raise NotImplementedError("The subclass must override this method")
 
     def __gt__(self, other):
-        return not (self.__lt__(other) or self.__eq(other))
+        return not (self.__lt__(other) or self.__eq__(other))
 
     def __ne__(self, other):
         return not self.__eq__(other)

lastfm/event.py

@@ -287,11 +287,12 @@ class Event(LastfmBase, Cacheable, Sharable, Shoutable):
                      tag = data.findtext('tag')
                     )
 
-    def _default_params(self, extra_params = []):
+    def _default_params(self, extra_params = None):
         if not self.id:
             raise InvalidParametersError("id has to be provided.")
         params = {'event': self.id}
-        params.update(extra_params)
+        if extra_params is not None:
+            params.update(extra_params)
         return params
 
     @staticmethod

lastfm/group.py

@@ -215,11 +215,12 @@ class Group(LastfmBase, Cacheable):
                 url = u.findtext('url')
             )
         
-    def _default_params(self, extra_params = {}):
+    def _default_params(self, extra_params = None):
         if not self.name:
             raise InvalidParametersError("group has to be provided.")
         params = {'group': self.name}
-        params.update(extra_params)
+        if extra_params is not None:
+            params.update(extra_params)
         return params
     
     @staticmethod

lastfm/mixins/cacheable.py

@@ -51,3 +51,7 @@ class Cacheable(object):
             #print "not already registered: %s" % ob.__class__
             Cacheable.registry[ob.__class__][key] = ob
             return (ob, False)
+        
+    @staticmethod
+    def _hash_func(*args, **kwds):
+        raise NotImplementedError("The subclass must override this method")

lastfm/mixins/sharable.py

@@ -26,5 +26,8 @@ class Sharable(object):
         params['recipient'] = ",".join(recipient)
         self._api._post_data(params)
         
-    def _default_params(self, extra_params = {}):
+    def _default_params(self, extra_params = None):
-        return extra_params
+        if extra_params is not None:
+            return extra_params
+        else:
+            return {}

lastfm/mixins/shoutable.py

@@ -34,8 +34,11 @@ class Shoutable(object):
         """recent shout for this subject"""
         pass
     
-    def _default_params(self, extra_params = {}):
+    def _default_params(self, extra_params = None):
-        return extra_params
+        if extra_params is not None:
+            return extra_params
+        else:
+            return {}
     
 from datetime import datetime
 import time

lastfm/mixins/taggable.py

@@ -66,5 +66,8 @@ class Taggable(object):
         self._api._post_data(params)
         self._tags = None
         
-    def _default_params(self, extra_params = {}):
+    def _default_params(self, extra_params = None):
-        return extra_params
+        if extra_params is not None:
+            return extra_params
+        else:
+            return {}

lastfm/tag.py

@@ -227,11 +227,12 @@ class Tag(LastfmBase, Cacheable, Searchable):
                 for t in data.findall('tag')
                 ]
 
-    def _default_params(self, extra_params = {}):
+    def _default_params(self, extra_params = None):
         if not self.name:
             raise InvalidParametersError("tag has to be provided.")
         params = {'tag': self.name}
-        params.update(extra_params)
+        if extra_params is not None:
+            params.update(extra_params)
         return params
 
     @staticmethod

lastfm/track.py

@@ -272,11 +272,12 @@ class Track(LastfmBase, Cacheable, Sharable, Searchable, Taggable):
         t._fill_info()
         return t
 
-    def _default_params(self, extra_params = {}):
+    def _default_params(self, extra_params = None):
         if not (self.artist and self.name):
             raise InvalidParametersError("artist and track have to be provided.")
         params = {'artist': self.artist.name, 'track': self.name}
-        params.update(extra_params)
+        if extra_params is not None:
+            params.update(extra_params)
         return params
 
     @staticmethod

lastfm/user.py

@@ -621,11 +621,12 @@ class User(LastfmBase, Cacheable, Shoutable):
         user._stats = Stats(subject = user, playcount = data.findtext('playcount'))
         return user
         
-    def _default_params(self, extra_params = {}):
+    def _default_params(self, extra_params = None):
         if not self.name:
             raise InvalidParametersError("user has to be provided.")
         params = {'user': self.name}
-        params.update(extra_params)
+        if extra_params is not None:
+            params.update(extra_params)
         return params
 
     @staticmethod
@@ -883,11 +884,12 @@ class User(LastfmBase, Cacheable, Shoutable):
             self._api._post_data(params)
             self._tracks = None
 
-        def _default_params(self, extra_params = {}):
+        def _default_params(self, extra_params = None):
             if not self.user.name:
                 raise InvalidParametersError("user has to be provided.")
             params = {'user': self.user.name}
-            params.update(extra_params)
+            if extra_params is not None:
+                params.update(extra_params)
             return params
 
         @staticmethod