Mention that crc32 and adler32 are available in a different module (zlib).
Some people look for them in hashlib.
diff --git a/Lib/hashlib.py b/Lib/hashlib.py
index f7c0211..13124e2 100644
--- a/Lib/hashlib.py
+++ b/Lib/hashlib.py
@@ -18,6 +18,9 @@
More algorithms may be available on your platform but the above are
guaranteed to exist.
+NOTE: If you want the adler32 or crc32 hash functions they are available in
+the zlib module.
+
Choose your hash function wisely. Some have known collision weaknesses.
sha384 and sha512 will be slow on 32 bit platforms.