diff -r 58674a027d10 Lib/idlelib/GrepDialog.py
--- a/Lib/idlelib/GrepDialog.py	Wed Jan 07 23:49:06 2015 -0500
+++ b/Lib/idlelib/GrepDialog.py	Sat Jan 10 20:12:42 2015 +1100
@@ -11,6 +11,10 @@
 # EditorWindow -> GrepDialop -> OutputWindow -> EditorWindow
 
 def grep(text, io=None, flist=None):
+    """Opens the Find in Files dialog.
+
+    This global function handles getting the SearchEngine singleton object to
+    perform this operation."""
     root = text._root()
     engine = SearchEngine.get(root)
     if not hasattr(engine, "_grepdialog"):
@@ -20,6 +24,7 @@
     dialog.open(text, searchphrase, io)
 
 class GrepDialog(SearchDialogBase):
+    """Creates the modal search dialog for the Find in Files dialog."""
 
     title = "Find in Files Dialog"
     icon = "Grep"
@@ -32,6 +37,13 @@
         self.recvar = BooleanVar(root)
 
     def open(self, text, searchphrase, io=None):
+        """Opens the Find in Files search dialog.
+
+        Arguments:
+        text -- a MultiCall object containing the text information
+        searchphrase -- the search text to populate the search field with
+        io -- an IOBinding object containing the file information (default None)
+        """
         SearchDialogBase.open(self, text, searchphrase)
         if io:
             path = io.filename or ""
@@ -44,10 +56,12 @@
         self.globvar.set(os.path.join(dir, "*" + tail))
 
     def create_entries(self):
+        """Creates the text field UI elements, including the "In files" text field."""
         SearchDialogBase.create_entries(self)
         self.globent = self.make_entry("In files:", self.globvar)[0]
 
     def create_other_buttons(self):
+        """Creates the "Recursive" checkbox."""
         f = self.make_frame()[0]
 
         btn = Checkbutton(f, anchor="w",
@@ -57,10 +71,15 @@
         btn.select()
 
     def create_command_buttons(self):
+        """Creates the "Search Files" button."""
         SearchDialogBase.create_command_buttons(self)
         self.make_button("Search Files", self.default_command, 1)
 
     def default_command(self, event=None):
+        """Creates the output window for the results and begins the grepping.
+
+        Arguments:
+        event -- Not used. (default None)"""
         prog = self.engine.getprog()
         if not prog:
             return
@@ -77,6 +96,11 @@
             sys.stdout = save
 
     def grep_it(self, prog, path):
+        """Performs the grepping.
+
+        Arguments:
+        prog -- The regex object to use for grepping.
+        path -- The parent folder to search."""
         dir, base = os.path.split(path)
         list = self.findfiles(dir, base, self.recvar.get())
         list.sort()
diff -r 58674a027d10 Lib/idlelib/ReplaceDialog.py
--- a/Lib/idlelib/ReplaceDialog.py	Wed Jan 07 23:49:06 2015 -0500
+++ b/Lib/idlelib/ReplaceDialog.py	Sat Jan 10 20:12:42 2015 +1100
@@ -6,6 +6,10 @@
 
 
 def replace(text):
+    """Opens the Replace dialog.
+
+    This global function handles getting the SearchEngine singleton object to
+    perform this operation."""
     root = text._root()
     engine = SearchEngine.get(root)
     if not hasattr(engine, "_replacedialog"):
@@ -15,6 +19,7 @@
 
 
 class ReplaceDialog(SearchDialogBase):
+    """Creates the modal search dialog for the Replace dialog."""
 
     title = "Replace Dialog"
     icon = "Replace"
@@ -24,6 +29,13 @@
         self.replvar = StringVar(root)
 
     def open(self, text):
+        """Opens the Replace dialog as a modal window.
+
+        This method is overriden by subclasses to customize the UI elements.
+
+        Arguments:
+        text -- a MultiCall object containing the text information
+        """
         SearchDialogBase.open(self, text)
         try:
             first = text.index("sel.first")
@@ -39,10 +51,12 @@
         self.ok = 1
 
     def create_entries(self):
+        """Create the main text fields for the Replace dialog."""
         SearchDialogBase.create_entries(self)
         self.replent = self.make_entry("Replace with:", self.replvar)[0]
 
     def create_command_buttons(self):
+        """Create the Find, Replace, and Replace All buttons."""
         SearchDialogBase.create_command_buttons(self)
         self.make_button("Find", self.find_it)
         self.make_button("Replace", self.replace_it)
@@ -50,6 +64,7 @@
         self.make_button("Replace All", self.replace_all)
 
     def find_it(self, event=None):
+        """The Find button's handler function. Performs a Find operation."""
         self.do_find(0)
 
     def replace_it(self, event=None):
@@ -57,14 +72,16 @@
             self.do_replace()
 
     def default_command(self, event=None):
+        """The Replace button's handler function. Performs a Find and
+        Replace operation, then Find the next instance of the Find text."""
         if self.do_find(self.ok):
             if self.do_replace():   # Only find next match if replace succeeded.
                                     # A bad re can cause a it to fail.
                 self.do_find(0)
 
     def _replace_expand(self, m, repl):
-        """ Helper function for expanding a regular expression
-            in the replace field, if needed. """
+        """Helper function for expanding a regular expression in the replace
+        field, if needed."""
         if self.engine.isre():
             try:
                 new = m.expand(repl)
@@ -77,6 +94,8 @@
         return new
 
     def replace_all(self, event=None):
+        """The Replace All button's handler function. Performs a Replace
+        operation for all instances of the text."""
         prog = self.engine.getprog()
         if not prog:
             return
@@ -126,6 +145,7 @@
         self.close()
 
     def do_find(self, ok=0):
+        """Performs a Find operation."""
         if not self.engine.getprog():
             return False
         text = self.text
@@ -142,6 +162,7 @@
         return True
 
     def do_replace(self):
+        """Performs a Replace operation."""
         prog = self.engine.getprog()
         if not prog:
             return False
diff -r 58674a027d10 Lib/idlelib/SearchDialog.py
--- a/Lib/idlelib/SearchDialog.py	Wed Jan 07 23:49:06 2015 -0500
+++ b/Lib/idlelib/SearchDialog.py	Sat Jan 10 20:12:42 2015 +1100
@@ -4,6 +4,7 @@
 from idlelib.SearchDialogBase import SearchDialogBase
 
 def _setup(text):
+    """Creates and returns the singleton SearchEngine object."""
     root = text._root()
     engine = SearchEngine.get(root)
     if not hasattr(engine, "_searchdialog"):
@@ -11,27 +12,52 @@
     return engine._searchdialog
 
 def find(text):
+    """Opens the Find dialog.
+
+    This global function handles getting the SearchEngine singleton object to
+    perform this operation."""
     pat = text.get("sel.first", "sel.last")
     return _setup(text).open(text,pat)
 
 def find_again(text):
+    """Performs the previous Find operation again. If there was no previous
+    Find, then opens the Find dialog.
+
+    This global function handles getting the SearchEngine singleton object to
+    perform this operation."""
     return _setup(text).find_again(text)
 
 def find_selection(text):
+    """Opens the Find dialog, prepopulating the search phrase with the
+    currently selected text.
+
+    This global function handles getting the SearchEngine singleton object to
+    perform this operation."""
     return _setup(text).find_selection(text)
 
 class SearchDialog(SearchDialogBase):
+    """Creates the modal search dialog for the Find dialog."""
 
     def create_widgets(self):
+        """Creates all of the initial set of base UI elements and binds the
+        Enter/Esc keys. For SearchDialog, additionally creates the Find Next
+        button."""
         f = SearchDialogBase.create_widgets(self)
         self.make_button("Find Next", self.default_command, 1)
 
     def default_command(self, event=None):
+        """The default command is run when Enter is pressed. For SearchDialog,
+        it is the Find operation.
+
+        Arguments:
+        event -- Not used. (default None)"""
         if not self.engine.getprog():
             return
         self.find_again(self.text)
 
     def find_again(self, text):
+        """Performs the previous Find operation again. If there was no previous
+        Find, then opens the Find dialog."""
         if not self.engine.getpat():
             self.open(text)
             return False
@@ -61,6 +87,8 @@
             return False
 
     def find_selection(self, text):
+        """Performs a Find based on the currently selected text and previously
+        set Find options."""
         pat = text.get("sel.first", "sel.last")
         if pat:
             self.engine.setcookedpat(pat)
diff -r 58674a027d10 Lib/idlelib/SearchDialogBase.py
--- a/Lib/idlelib/SearchDialogBase.py	Wed Jan 07 23:49:06 2015 -0500
+++ b/Lib/idlelib/SearchDialogBase.py	Sat Jan 10 20:12:42 2015 +1100
@@ -45,7 +45,15 @@
         self.top = None
 
     def open(self, text, searchphrase=None):
-        "Make dialog visible on top of others and ready to use."
+        """Opens the search dialog as a modal window.
+
+        This method is overriden by subclasses to customize the UI elements.
+
+        Arguments:
+        text -- a MultiCall object containing the text information
+        searchphrase -- The text to populate the search field with. If None,
+          the previous search phrase is reused
+        """
         self.text = text
         if not self.top:
             self.create_widgets()
@@ -53,21 +61,23 @@
             self.top.deiconify()
             self.top.tkraise()
         if searchphrase:
+            # populate the Find field
             self.ent.delete(0,"end")
             self.ent.insert("end",searchphrase)
         self.ent.focus_set()
         self.ent.selection_range(0, "end")
         self.ent.icursor(0)
-        self.top.grab_set()
+        self.top.grab_set() # make this dialog window modal
 
     def close(self, event=None):
-        "Put dialog away for later use."
+        """Closes the modal search dialog."""
         if self.top:
-            self.top.grab_release()
+            self.top.grab_release() # un-modal this dialog window
             self.top.withdraw()
 
     def create_widgets(self):
-        '''Create basic 3 row x 3 col search (find) dialog.
+        '''Create basic 3 row x 3 col search (find) dialog and binds the
+        Enter/Esc keys.
 
         Other dialogs override subsidiary create_x methods as needed.
         Replace and Find-in-Files add another entry row.
diff -r 58674a027d10 Lib/idlelib/SearchEngine.py
--- a/Lib/idlelib/SearchEngine.py	Wed Jan 07 23:49:06 2015 -0500
+++ b/Lib/idlelib/SearchEngine.py	Sat Jan 10 20:12:42 2015 +1100
@@ -91,6 +91,7 @@
         return prog
 
     def report_error(self, pat, msg, col=-1):
+        """Display a dialog box reporting an error with the Find regex."""
         # Derived class could override this with something fancier
         msg = "Error: " + str(msg)
         if pat:
@@ -141,6 +142,15 @@
         return res
 
     def search_forward(self, text, prog, line, col, wrap, ok=0):
+        """Highlight the text for the next match.
+
+        Arguments:
+        text -- a MultiCall object containing the text information
+        prog -- A regex pattern object.
+        line -- The line number to start searching from.
+        col -- The column number to start searching from.
+        wrap -- If True, continue search past the end.
+        ok -- See search_text()"""
         wrapped = 0
         startline = line
         chars = text.get("%d.0" % line, "%d.0" % (line+1))
@@ -163,6 +173,15 @@
         return None
 
     def search_backward(self, text, prog, line, col, wrap, ok=0):
+        """Highlight the text for the previous match.
+
+        Arguments:
+        text -- a MultiCall object containing the text information
+        prog -- A regex pattern object.
+        line -- The line number to start searching from.
+        col -- The column number to start searching from.
+        wrap -- If True, continue search past the end.
+        ok -- See search_text()"""
         wrapped = 0
         startline = line
         chars = text.get("%d.0" % line, "%d.0" % (line+1))
@@ -210,8 +229,7 @@
     return found
 
 def get_selection(text):
-    '''Return tuple of 'line.col' indexes from selection or insert mark.
-    '''
+    '''Return tuple of 'line.col' indexes from selection or insert mark.'''
     try:
         first = text.index("sel.first")
         last = text.index("sel.last")