Clarify that len() of a Unicode string returns the number of storage units,

not abstract characters.

diff --git a/Doc/lib/libfuncs.tex b/Doc/lib/libfuncs.tex
index 4a0efdb78f7b4ce32ec06f28f80666375f1bc483..491e0fef7d9aa7f5e6afefe04dba06a781957ce0 100644 (file)
--- a/Doc/lib/libfuncs.tex
+++ b/Doc/lib/libfuncs.tex
@@ -568,6 +568,10 @@ def my_import(name):
 \begin{funcdesc}{len}{s}
   Return the length (the number of items) of an object.  The argument
   may be a sequence (string, tuple or list) or a mapping (dictionary).
+  In the case of Unicode strings, \function{len()} returns the number
+  of storage units, not abstract characters.  In particular, when a
+  surrogate pair is encountered, each component of the pair is counted
+  as a separate character.
 \end{funcdesc}
 
 \begin{funcdesc}{list}{\optional{sequence}}