Merged revisions 73771,73811,73840,73842,73848-73849,73861,73957-73960,73964-73969,73972-73974,73977,73981,73984,74065,74113 via svnmerge from
svn+ssh://pythondev@svn.python.org/sandbox/trunk/2to3/lib2to3

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  r73771 | benjamin.peterson | 2009-07-02 10:56:55 -0500 (Thu, 02 Jul 2009) | 1 line

  force the imports fixer to be run after the import one #6400
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  r73811 | benjamin.peterson | 2009-07-03 09:03:14 -0500 (Fri, 03 Jul 2009) | 1 line

  check for sep, not pathsep when looking for a subpackage #6408
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  r73840 | benjamin.peterson | 2009-07-04 09:52:28 -0500 (Sat, 04 Jul 2009) | 1 line

  don't print diffs by default; it's annoying
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  r73842 | benjamin.peterson | 2009-07-04 09:58:46 -0500 (Sat, 04 Jul 2009) | 1 line

  complain when not showing diffs or writing
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  r73848 | alexandre.vassalotti | 2009-07-04 23:38:19 -0500 (Sat, 04 Jul 2009) | 2 lines

  Fix test_refactor_stdin to handle print_output() method with 4 arguments.
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  r73849 | alexandre.vassalotti | 2009-07-04 23:43:18 -0500 (Sat, 04 Jul 2009) | 5 lines

  Issue 2370: Add fixer for the removal of operator.isCallable() and
  operator.sequenceIncludes().

  Patch contributed by Jeff Balogh (and updated by me).
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  r73861 | benjamin.peterson | 2009-07-05 09:15:53 -0500 (Sun, 05 Jul 2009) | 1 line

  cleanup and use unicode where appropiate
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  r73957 | benjamin.peterson | 2009-07-11 15:49:56 -0500 (Sat, 11 Jul 2009) | 1 line

  fix calls to str() with unicode()
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  r73958 | benjamin.peterson | 2009-07-11 15:51:51 -0500 (Sat, 11 Jul 2009) | 1 line

  more str() -> unicode()
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  r73959 | benjamin.peterson | 2009-07-11 16:40:08 -0500 (Sat, 11 Jul 2009) | 1 line

  add tests for refactor_dir()
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  r73960 | benjamin.peterson | 2009-07-11 16:44:32 -0500 (Sat, 11 Jul 2009) | 1 line

  don't parse files just because they end with 'py' (no dot)
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  r73964 | benjamin.peterson | 2009-07-11 17:30:15 -0500 (Sat, 11 Jul 2009) | 1 line

  simplify
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  r73965 | benjamin.peterson | 2009-07-11 17:31:30 -0500 (Sat, 11 Jul 2009) | 1 line

  remove usage of get_prefix()
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  r73966 | benjamin.peterson | 2009-07-11 17:33:35 -0500 (Sat, 11 Jul 2009) | 1 line

  revert unintended change in 73965
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  r73967 | benjamin.peterson | 2009-07-11 17:34:44 -0500 (Sat, 11 Jul 2009) | 1 line

  avoid expensive checks and assume the node did change
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  r73968 | benjamin.peterson | 2009-07-11 20:46:46 -0500 (Sat, 11 Jul 2009) | 1 line

  use a regular dict for the heads to avoid adding lists in the loop
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  r73969 | benjamin.peterson | 2009-07-11 20:50:43 -0500 (Sat, 11 Jul 2009) | 1 line

  prefix headnode functions with '_'
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  r73972 | benjamin.peterson | 2009-07-11 21:25:45 -0500 (Sat, 11 Jul 2009) | 1 line

  try to make the head node dict as sparse as possible
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  r73973 | benjamin.peterson | 2009-07-11 21:59:49 -0500 (Sat, 11 Jul 2009) | 1 line

  a better idea; add an option to *not* print diffs
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  r73974 | benjamin.peterson | 2009-07-11 22:00:29 -0500 (Sat, 11 Jul 2009) | 1 line

  add space
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  r73977 | benjamin.peterson | 2009-07-12 10:16:07 -0500 (Sun, 12 Jul 2009) | 1 line

  update get_headnode_dict tests for recent changes
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  r73981 | benjamin.peterson | 2009-07-12 12:06:39 -0500 (Sun, 12 Jul 2009) | 4 lines

  detect when "from __future__ import print_function" is given

  Deprecate the 'print_function' option and the -p flag
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  r73984 | benjamin.peterson | 2009-07-12 16:16:37 -0500 (Sun, 12 Jul 2009) | 1 line

  add tests for Call; thanks Joe Amenta
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  r74065 | benjamin.peterson | 2009-07-17 12:52:49 -0500 (Fri, 17 Jul 2009) | 1 line

  pathname2url and url2pathname are in urllib.request not urllib.parse #6496
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  r74113 | benjamin.peterson | 2009-07-20 08:56:57 -0500 (Mon, 20 Jul 2009) | 1 line

  fix deprecation warnings in tests
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diff --git a/Lib/lib2to3/main.py b/Lib/lib2to3/main.py
index cf4adf7..9238807 100644
--- a/Lib/lib2to3/main.py
+++ b/Lib/lib2to3/main.py
@@ -4,19 +4,31 @@
 
 import sys
 import os
+import difflib
 import logging
 import shutil
 import optparse
 
 from . import refactor
 
+
+def diff_texts(a, b, filename):
+    """Return a unified diff of two strings."""
+    a = a.splitlines()
+    b = b.splitlines()
+    return difflib.unified_diff(a, b, filename, filename,
+                                "(original)", "(refactored)",
+                                lineterm="")
+
+
 class StdoutRefactoringTool(refactor.MultiprocessRefactoringTool):
     """
     Prints output to stdout.
     """
 
-    def __init__(self, fixers, options, explicit, nobackups):
+    def __init__(self, fixers, options, explicit, nobackups, show_diffs):
         self.nobackups = nobackups
+        self.show_diffs = show_diffs
         super(StdoutRefactoringTool, self).__init__(fixers, options, explicit)
 
     def log_error(self, msg, *args, **kwargs):
@@ -42,9 +54,18 @@
         if not self.nobackups:
             shutil.copymode(backup, filename)
 
-    def print_output(self, lines):
-        for line in lines:
-            print line
+    def print_output(self, old, new, filename, equal):
+        if equal:
+            self.log_message("No changes to %s", filename)
+        else:
+            self.log_message("Refactored %s", filename)
+            if self.show_diffs:
+                for line in diff_texts(old, new, filename):
+                    print line
+
+
+def warn(msg):
+    print >> sys.stderr, "WARNING: %s" % (msg,)
 
 
 def main(fixer_pkg, args=None):
@@ -70,9 +91,12 @@
     parser.add_option("-l", "--list-fixes", action="store_true",
                       help="List available transformations (fixes/fix_*.py)")
     parser.add_option("-p", "--print-function", action="store_true",
-                      help="Modify the grammar so that print() is a function")
+                      help="DEPRECATED Modify the grammar so that print() is "
+                          "a function")
     parser.add_option("-v", "--verbose", action="store_true",
                       help="More verbose logging")
+    parser.add_option("--no-diffs", action="store_true",
+                      help="Don't show diffs of the refactoring")
     parser.add_option("-w", "--write", action="store_true",
                       help="Write back modified files")
     parser.add_option("-n", "--nobackups", action="store_true", default=False,
@@ -81,6 +105,11 @@
     # Parse command line arguments
     refactor_stdin = False
     options, args = parser.parse_args(args)
+    if not options.write and options.no_diffs:
+        warn("not writing files and not printing diffs; that's not very useful")
+    if options.print_function:
+        warn("-p is deprecated; "
+             "detection of from __future__ import print_function is automatic")
     if not options.write and options.nobackups:
         parser.error("Can't use -n without -w")
     if options.list_fixes:
@@ -90,13 +119,13 @@
         if not args:
             return 0
     if not args:
-        print >>sys.stderr, "At least one file or directory argument required."
-        print >>sys.stderr, "Use --help to show usage."
+        print >> sys.stderr, "At least one file or directory argument required."
+        print >> sys.stderr, "Use --help to show usage."
         return 2
     if "-" in args:
         refactor_stdin = True
         if options.write:
-            print >>sys.stderr, "Can't write to stdin."
+            print >> sys.stderr, "Can't write to stdin."
             return 2
 
     # Set up logging handler
@@ -104,7 +133,6 @@
     logging.basicConfig(format='%(name)s: %(message)s', level=level)
 
     # Initialize the refactoring tool
-    rt_opts = {"print_function" : options.print_function}
     avail_fixes = set(refactor.get_fixers_from_package(fixer_pkg))
     unwanted_fixes = set(fixer_pkg + ".fix_" + fix for fix in options.nofix)
     explicit = set()
@@ -119,8 +147,8 @@
     else:
         requested = avail_fixes.union(explicit)
     fixer_names = requested.difference(unwanted_fixes)
-    rt = StdoutRefactoringTool(sorted(fixer_names), rt_opts, sorted(explicit),
-                               options.nobackups)
+    rt = StdoutRefactoringTool(sorted(fixer_names), None, sorted(explicit),
+                               options.nobackups, not options.no_diffs)
 
     # Refactor all files and directories passed as arguments
     if not rt.errors: