http://docs.python.org/reference/compound_stmts.html#with

This documentation refers to "context expressions" in two places.  However, it never really defines what a context expression is.  The formal syntax that's presented is this:

with_stmt ::=  "with" with_item ("," with_item)* ":" suite
with_item ::=  expression ["as" target]

As best I can tell, the context expression is essentially the with_item.  If that's the case, I propose one of the following:

 1) The formal syntax is changed so that "with_item" becomes "context_expression".
 2) References to "context expression" change to "with item".
 3) The "context expression" is defined to be the with_item in the formal syntax at some point in the documentation.