mimetypes.guess_extension('text/plain') == '.ksh' ???

Lib/mimetypes.py

Index: Lib/mimetypes.py
===================================================================
--- Lib/mimetypes.py	(revisão 86582)
+++ Lib/mimetypes.py	(cópia de trabalho)
@@ -173,7 +173,7 @@
                     extensions.append(ext)
         return extensions
 
-    def guess_extension(self, type, strict=True):
+    def guess_extension(self, type, strict=True, all_exts=False):
         """Guess the extension for a file based on its MIME type.
 
         Return value is a string giving a filename extension,
@@ -188,8 +188,11 @@
         """
         extensions = self.guess_all_extensions(type, strict)
         if not extensions:
-            return None
-        return extensions[0]
+            extensions.append(None)
+        if all_exts:
+            return tuple(extensions)
+        else:
+            return extensions[0]
 
     def read(self, filename, strict=True):
         """
@@ -304,7 +307,7 @@
         init()
     return _db.guess_all_extensions(type, strict)
 
-def guess_extension(type, strict=True):
+def guess_extension(type, strict=True, all_exts=False):
     """Guess the extension for a file based on its MIME type.
 
     Return value is a string giving a filename extension, including the
@@ -318,7 +321,7 @@
     """
     if _db is None:
         init()
-    return _db.guess_extension(type, strict)
+    return _db.guess_extension(type, strict, all_exts)
 
 def add_type(type, ext, strict=True):
     """Add a mapping between a type and an extension.