guess_extension(): Revise documentation string to be more clear. If not
inited, call init().
diff --git a/Lib/mimetypes.py b/Lib/mimetypes.py
index 6bc55ea..cb28afe 100644
--- a/Lib/mimetypes.py
+++ b/Lib/mimetypes.py
@@ -71,10 +71,13 @@
Return value is a string giving a filename extension, including the
leading dot ('.'). The extension is not guaranteed to have been
- associated with any particular data stream, but has been known to be
- used for streams of the MIME type given by `type'. If `type' is not
- known, None is returned.
+ associated with any particular data stream, but would be mapped to the
+ MIME type `type' by guess_type(). If no extension can be guessed for
+ `type', None is returned.
"""
+ global inited
+ if not inited:
+ init()
type = string.lower(type)
for ext, stype in types_map.items():
if type == stype: