Cameron Simpson於 2019年11月1日星期五 UTC+8下午5時28分42秒寫道： > On 31Oct2019 22:03, Jach Fong <jf...@ms4.hinet.net> wrote: > >Cameron Simpson於 2019年11月1日星期五 UTC+8下午12時13分45秒寫道： > >> On 31Oct2019 20:44, Jach Fong <jf...@ms4.hinet.net> wrote: > >> >The script test.py is something like this: > >> >-------test.py > >> >from pyeds import fsm > >> >... > >> >class Rule_Parse: > >> > def __init__(self): > >> > ... > >> > self.current_char = '' > >> >... > >> >def main(input_str): > >> > for c in input_str: > >> > ... > >> > rule.current_char = c > >> > ... > >> > > >> >if __name__ == '__main__': > >> > input_str = '(NNS(acoustics) & RB(not)) | JJ(muted)' > >> > rule = Rule_Parse() > >> > main(input_str) > >> > ... > >> > > >> >----------- > >> >The test.py can run correctly under command box: > >> >D:\Works\Python\pyeds-master\src>py test.py > >> > > >> >but fails when running under interpreter: > >> >D:\Works\Python\pyeds-master\src>py > >> >Python 3.4.4 (v3.4.4:737efcadf5a6, Dec 20 2015, 19:28:18) [MSC v.1600 32 > >> >bit (Intel)] on win32 > >> >Type "help", "copyright", "credits" or "license" for more information. > >> >>>> from test import * > >> >>>> input_str = "(NNS(acoustics) & RB(not)) | JJ(muted)" > >> >>>> rule = Rule_Parse() > >> >>>> main(input_str) > >> >Traceback (most recent call last): > >> > File "<stdin>", line 1, in <module> > >> > File "D:\Works\Python\pyeds-master\src\test.py", line 229, in main > >> > rule.current_char = c > >> >NameError: name 'rule' is not defined > >> >>>> > >> > > >> >I did check the globals using dir() and the 'rule' is there, no doubt. > >> > >> It matters how you checked this. This isn't apparent. > [...] > >Yes, the 'if' body is not executed when I import test.py under > >interpreter, that's why I manually execute them there. > >What puzzles me is that the globals() has a 'rule' object in both > >cases. Why this one doesn't work? > > I think I have misinterpreted what you've done. > > The globals are your current module's namespace, and functions defines > in a module are bound to that module's namespace. > > Strip your test.py back. A lot. Try this: > > def main(): > print(rule) > > Now, let's use that: > > Python 3.7.4 (default, Sep 28 2019, 13:34:38) > [Clang 8.0.0 (clang-800.0.42.1)] on darwin > Type "help", "copyright", "credits" or "license" for more information. > >>> import test > >>> test.main() > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > File "/Users/cameron/tmp/d1/test.py", line 2, in main > print(rule) > NameError: name 'rule' is not defined > > What's happening here? > > When we call main it tries to print "rule" from its module's globals. > > The first time you call it that doesn't exist, and we get your error. > > Setting rule=1 in the interpreter's space doesn't help (the stuff below > if from the same session continued from above): > > >>> rule=1 > >>> test.main() > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > File "/Users/cameron/tmp/d1/test.py", line 2, in main > print(rule) > NameError: name 'rule' is not defined > > But if we define rule in the "test" module things improve: > > >>> test.rule=2 > >>> test.main() > 2 > > Importing main from test doesn't change where it looks for its globals: > > >>> from test import main as my_main > >>> my_main() > 2 > > That value (2) is still coming out of the test module. > > Cheers, > Cameron Simpson <c...@cskk.id.au>
I didn't noticed that the interpreter has its own globals. Thanks for reminding. --Jach -- https://mail.python.org/mailman/listinfo/python-list
