在Python中一次遍历String单词

通过三种不同的方式逐字逐字地遍历文件的内容（以古腾堡计划的《绿野仙踪》为例）：

from __future__ import with_statementimport timeimport refrom cStringIO import StringIOdef word_iter_std(filename):    start = time.time()    with open(filename) as f:        for line in f: for word in line.split():     yield word    print 'iter_std took %0.6f seconds' % (time.time() - start)def word_iter_re(filename):    start = time.time()    with open(filename) as f:        txt = f.read()    for word in re.finditer('w+', txt):        yield word    print 'iter_re took %0.6f seconds' % (time.time() - start)def word_iter_stringio(filename):    start = time.time()    with open(filename) as f:        io = StringIO(f.read())    for line in io:        for word in line.split(): yield word    print 'iter_io took %0.6f seconds' % (time.time() - start)woo = '/tmp/woo.txt'for word in word_iter_std(woo): passfor word in word_iter_re(woo): passfor word in word_iter_stringio(woo): pass

导致：

% python /tmp/junk.pyiter_std took 0.016321 secondsiter_re took 0.028345 secondsiter_io took 0.016230 seconds