SList.grep() supports optional 'field' argument

IPython/genutils.py

@@ -1052,25 +1052,40 b' class SList(list):'
     
     p = paths = property(get_paths)
 
-    def grep(self, pattern, prune = False):
+    def grep(self, pattern, prune = False, field = None):
         """ Return all strings matching 'pattern' (a regex or callable) 
         
         This is case-insensitive. If prune is true, return all items
         NOT matching the pattern.
         
+        If field is specified, the match must occur in the specified 
+        whitespace-separated field.
+               
         Examples::
         
             a.grep( lambda x: x.startswith('C') )
             a.grep('Cha.*log', prune=1)
+            a.grep('chm', field=-1)
         """
+        
+        def match_target(s):
+            if field is None:
+                return s
+            parts = s.split()
+            try:
+                tgt = parts[field]
+                return tgt
+            except IndexError:
+                return ""
+        
         if isinstance(pattern, basestring):
             pred = lambda x : re.search(pattern, x, re.IGNORECASE)
         else:
             pred = pattern
         if not prune:
-            return SList([el for el in self if pred(el)])
+            return SList([el for el in self if pred(match_target(el))])
         else:
-            return SList([el for el in self if not pred(el)])
+            return SList([el for el in self if not pred(match_target(el))])
     def fields(self, *fields):
         """ Collect whitespace-separated fields from string list
         
@@ -1083,6 +1098,7 b' class SList(list):'
         a.fields(0) is ['-rwxrwxrwx', 'drwxrwxrwx+']
         a.fields(1,0) is ['1 -rwxrwxrwx', '6 drwxrwxrwx+']
         (note the joining by space).
+        a.fields(-1) is ['ChangeLog', 'IPython']
         
         IndexErrors are ignored.
         

doc/ChangeLog

@@ -1,3 +1,7 b''
[phone]  Ville Vainio <[e-mail]>
+
+	* genutils.py: SList.grep supports 'field' argument
+
 2008-04-09  Ville Vainio <[e-mail]>
 
 	* deep_reload.py: do not crash on from __future__ import