The execfile() docs imply it acts on locals same as exec. But in truth

it acts more like assigning to keys in locals(), i.e. modifications to
function locals aren't reflected in the locals when execfile() returns.

diff --git a/Doc/lib/libfuncs.tex b/Doc/lib/libfuncs.tex
index 8eccc828a616820737cc8dc344f72af206242860..ec7ce86eedb457a368be3fcf35994ac46e62cd69 100644 (file)
--- a/Doc/lib/libfuncs.tex
+++ b/Doc/lib/libfuncs.tex
@@ -257,6 +257,13 @@ class instances are callable if they have a \method{__call__()} method.
   If both dictionaries are omitted, the expression is executed in the
   environment where \function{execfile()} is called.  The return value is
   \code{None}.
+
+  \strong{Warning:} The default \var{locals} act as described for function
+  \function{locals()} below:  modifications to the default \var{locals}
+  dictionary should not be attempted.  Pass an explicit \var{locals}
+  dictionary if you need to see effects of the code on \var{locals} after
+  function \function{execfile()} returns.  \function{execfile()} cannot
+  be used reliably to modify a function's locals.
 \end{funcdesc}
 
 \begin{funcdesc}{file}{filename\optional{, mode\optional{, bufsize}}}