En Tue, 26 Feb 2008 12:33:01 -0200, <[EMAIL PROTECTED]> escribió: > On Feb 26, 8:14 am, Marc 'BlackJack' Rintsch <[EMAIL PROTECTED]> wrote:
>> I guess it's the method lookup that's the slow part. Factor it out of >> the >> loop and measure again:: >> >> adict_get = adict.get >> for _ in xrange(M): >> for k in keys1: >> r = adict_get(k, None) >> for k in keys2: >> r = adict_get(k, None) > > Can't be. The string 'get' is only hashed once, since it's hard-coded > into the script, and looking it up can't be any slower than looking up > __getitem__. In the original code, the 'get' method is searched a lot of times (every time it's called), not just once; Python can't assume that it remains the same at every invocation. And __getitem__ isn't searched by name; there is a predefined slot in the type structure for it. In case the method were overriden in Python code, the slot is replaced with a wrapper function that calls the Python code. -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
