性能分析

__init__(self,verbose=False):
        self.verbose = verbose
def __enter__(self):
    self.start = clock()
    return self

def __exit__(self,*args):
    self.end = clock()
    self.secs = self.end - self.start
    self.msecs = self.secs * 1000  # millisecs
    if self.verbose:
        print 'elapsed time: %f ms' % self.msecs</code></pre>