Fix mutable default argument

lib/ansible/inventory/dir.py

@@ -81,7 +81,10 @@ def get_file_parser(hostsfile, groups, loader):
 class InventoryDirectory(object):
     ''' Host inventory parser for ansible using a directory of inventories. '''
 
-    def __init__(self, loader, groups=dict(), filename=C.DEFAULT_HOST_LIST):
+    def __init__(self, loader, groups=None, filename=C.DEFAULT_HOST_LIST):
+        if groups is None:
+            groups = dict()
+
         self.names = os.listdir(filename)
         self.names.sort()
         self.directory = filename

lib/ansible/inventory/ini.py

@@ -38,7 +38,10 @@ class InventoryParser(object):
     with their associated hosts and variable settings.
     """
 
-    def __init__(self, loader, groups=dict(), filename=C.DEFAULT_HOST_LIST):
+    def __init__(self, loader, groups=None, filename=C.DEFAULT_HOST_LIST):
+        if groups is None:
+            groups = dict()
+
         self._loader = loader
         self.filename = filename
 

lib/ansible/inventory/script.py

@@ -36,7 +36,9 @@ from ansible.module_utils.basic import json_dict_bytes_to_unicode
 class InventoryScript:
     ''' Host inventory parser for ansible using external inventory scripts. '''
 
-    def __init__(self, loader, groups=dict(), filename=C.DEFAULT_HOST_LIST):
+    def __init__(self, loader, groups=None, filename=C.DEFAULT_HOST_LIST):
+        if groups is None:
+            groups = dict()
 
         self._loader = loader
         self.groups = groups