On 11/16/2010 9:12 AM, Arnaud Delobelle wrote: > Hrvoje Niksic <hnik...@xemacs.org> writes: > >> m...@distorted.org.uk (Mark Wooding) writes: >> >>>> So even if the globals() dictionary is custom, its __setitem__ method is >>>> *not* called. >>> >>> Fascinating. Thank you. >> >> In case it's not obvious, that is because CPython assumes the type for >> many of its internal or semi-internal structures, and calls the >> appropriate functions, such as dict.__setitem__ (PyDict_SetItem in C) >> directly. So python doesn't break the encapsulation of dict itself, it >> just takes the liberty to assume that globals() is a non-subclassed >> dict, at least as far as __setitem__ is concerned. > > But it doesn't make this assumption for locals(). > That's because it reserves the right to optimize local storage without extending the mapping to allowing item setting.
regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon 2011 Atlanta March 9-17 http://us.pycon.org/ See Python Video! http://python.mirocommunity.org/ Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
