added popd

svn path=/trunk/matplotlib/; revision=716

Author: jdh2358

lib/matplotlib/cbook.py

@@ -411,7 +411,19 @@ def allpairs(x):
     assert( not allequal(('a', 'b')))    
 
 
+# python 2.2 dicts don't have pop
 def popd(d, *args):
+    """
+    Should behave like python2.3 pop method; d is a dict
+
+    # returns value for key and deletes item; raises a KeyError if key
+    # is not in dict
+    val = popd(d, key)
+
+    # returns value for key if key exists, else default.  Delete key,
+    # val item if it exists.  Will not raise a KeyError
+    val = popd(d, key, default)      
+    """
     if len(args)==1:
         key = args[0]
         val = d[key]