Piet van Oostrum wrote: >>>>>> Peter Otten <__pete...@web.de> (PO) wrote: > >>PO> $ cat x.py >>PO> import sys >>PO> globals().update(zip(*(range(110),)*2)) >>PO> y = 42 >>PO> print __name__ >>PO> if __name__ == "__main__": >>PO> a = b = 42 >>PO> print len(dir()) >>PO> from x import y as z >>PO> try: >>PO> print my_name >>PO> except NameError, e: >>PO> print 'unhandled NameError: "%s"' % e >>PO> sys.exit() > >>PO> $ python x.py >>PO> __main__ >>PO> 119 >>PO> x >>PO> 117 >>PO> unhandled NameError: "name 'my_name' is not defined" > > This is perfectly normal.
I'm not 100% sure of that. Just in case you didn't notice: I'm not the OP. The above piece of junk code was my attempt to keep as close to the code he posted while producing the same output that he got. > python x.py command runs normally (although > the globals().update is a very weird thing to do), until the from x > import y command. Then x.py is loaded again but now as the module 'x' > instead of '__main__'. Python doesn't know it's the same file, and > actually it doesn't want to know. It only knows it when you do import > twice on the same file. Not when you run it as a main script first and > then imports it. **This is a thing you shouldn't do**. > There are now two namespaces: one for __main__ and one for x. These are > distinct and have no relationship. > > The reason that the first number is 119 and the second is 117 is that > while importing x the variables a and b are not created. Your explanation is of course between 119 and 117% correct while I was only 99% serious... Cheers, Peter -- http://mail.python.org/mailman/listinfo/python-list
