From 6921c62436b10cd24d32f37c743d2ad8b7f1db37 2009-03-10 19:39:05
From: Fernando Perez <Fernando.Perez@berkeley.edu>
Date: 2009-03-10 19:39:05
Subject: [PATCH] Add tests and fixes to clearcmd extension, when using numpy.

---

diff --git a/IPython/Extensions/clearcmd.py b/IPython/Extensions/clearcmd.py
index 49fbd59..76cfbf7 100644
--- a/IPython/Extensions/clearcmd.py
+++ b/IPython/Extensions/clearcmd.py
@@ -5,43 +5,65 @@ import IPython.ipapi
 import gc
 ip = IPython.ipapi.get()
 
-
 def clear_f(self,arg):
     """ Clear various data (e.g. stored history data)
     
-    %clear out - clear output history
     %clear in  - clear input history
+    %clear out - clear output history
     %clear shadow_compress - Compresses shadow history (to speed up ipython)
     %clear shadow_nuke - permanently erase all entries in shadow history
     %clear dhist - clear dir history
+    %clear array - clear only variables that are NumPy arrays
+    
+    Examples:
+
+    In [1]: clear in
+    Flushing input history
+
+    In [2]: clear shadow_compress
+    Compressing shadow history
+
+    In [3]: clear shadow_nuke
+    Erased all keys from shadow history
+
+    In [4]: clear dhist
+    Clearing directory history
     """
     
     api = self.getapi()
+    user_ns = self.user_ns  # local lookup, heavily used
+        
+    
     for target in arg.split():
+
         if target == 'out':
-            print "Flushing output cache (%d entries)" % len(api.user_ns['_oh'])
+            print "Flushing output cache (%d entries)" % len(user_ns['_oh'])
             self.outputcache.flush()
+
         elif target == 'in':
             print "Flushing input history"
-            from IPython import iplib
             pc = self.outputcache.prompt_count + 1
             for n in range(1, pc):
                 key = '_i'+`n`
+                user_ns.pop(key,None)
                 try:
-                    del self.user_ns[key]
+                    del user_ns[key]
                 except: pass
             # must be done in-place
             self.input_hist[:] = ['\n'] * pc 
             self.input_hist_raw[:] = ['\n'] * pc
+
         elif target == 'array':
+            # Support cleaning up numpy arrays
             try:
-                pylab=ip.IP.pylab
-                for x in self.user_ns.keys():
-                    if isinstance(self.user_ns[x],pylab.arraytype):
-                        del self.user_ns[x]
+                from numpy import ndarray
+                # This must be done with items and not iteritems because we're
+                # going to modify the dict in-place.
+                for x,val in user_ns.items():
+                    if isinstance(val,ndarray):
+                        del user_ns[x]
             except AttributeError:
-                print "Clear array only available in -pylab mode"
-            gc.collect()                
+                print "Clear array only works if Numpy is available."
 
         elif target == 'shadow_compress':
             print "Compressing shadow history"
@@ -51,16 +73,15 @@ def clear_f(self,arg):
             print "Erased all keys from shadow history "
             for k in ip.db.keys('shadowhist/*'):
                 del ip.db[k]
+
         elif target == 'dhist':
             print "Clearing directory history"
-            del ip.user_ns['_dh'][:]
+            del user_ns['_dh'][:]
 
-            
+    gc.collect()        
+
+# Activate the extension
 ip.expose_magic("clear",clear_f)
 import ipy_completers
 ipy_completers.quick_completer(
- '%clear','in out shadow_nuke shadow_compress dhist')
-    
-
-
-
+    '%clear','in out shadow_nuke shadow_compress dhist')