Commit 38dc2a6b authored by Andrew M. Kuchling's avatar Andrew M. Kuchling

Simplify language

parent ac642875
......@@ -119,16 +119,13 @@ Kalle Svensson.}
%======================================================================
\section{PEP 289: Generator Expressions}
The iterator feature introduced in Python 2.2 makes it easier to write
programs that loop through large data sets without having the entire
data set in memory at one time. Programmers can use iterators and the
\module{itertools} module to write code in a fairly functional style.
% XXX avoid metaphor
List comprehensions have been the fly in the ointment because they
produce a Python list object containing all of the items, unavoidably
pulling them all into memory. When trying to write a
functionally-styled program, it would be natural to write something
The iterator feature introduced in Python 2.2 and the
\module{itertools} module make it easier to write programs that loop
through large data sets without having the entire data set in memory
at one time. List comprehensions don't fit into this picture very
well because they produce a Python list object containing all of the
items, unavoidably pulling them all into memory. When trying to write
a functionally-styled program, it would be natural to write something
like:
\begin{verbatim}
......@@ -148,7 +145,8 @@ for link in get_all_links():
The first form is more concise and perhaps more readable, but if
you're dealing with a large number of link objects the second form
would have to be used.
would have to be used to avoid having all link objects in memory at
the same time.
Generator expressions work similarly to list comprehensions but don't
materialize the entire list; instead they create a generator that will
......
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