On Wed, Nov 26, 2008 at 9:30 AM, TP <[EMAIL PROTECTED]> wrote: > Hi everybody, > > Here is a file "test_import_scope.py": > ########## > class a(): > import re > def __init__( self ): > if re.search( "to", "toto" ): > self.se = "ok!" > def print_se( self ): > print self.se > a().print_se() > ########## > > When python executes this file, we obtain an error: > > $ python test_import_scope.py > [...] > NameError: global name 're' is not defined > > Why?
Because Python doesn't look in class-scope when doing name resolution. It checks the local [function] namespace, then any nested [function] scopes (not applicable in this case), then the module/global namespace, and finally the builtins namespace. The class' namespace never comes into the equation. Consider this simpler example (remember that `import` assigns a module to its name in the importing scope): >>> class Foo(object): ... A=1 ... def foo(self): print A ... >>> Foo().foo() Traceback (most recent call last): File "<stdin>", line 1, in <module> File "<stdin>", line 3, in foo NameError: global name 'A' is not defined So in foo(), `A` can be accessed by Foo.A or self.A, but not just plain `A`. I agree it's not entirely intuitive, but remember that Python != Java. Cheers, Chris -- Follow the path of the Iguana... http://rebertia.com > > When the re module is imported in the __init__ function or out of the class > (at the top of the file), it works obviously perfectly. > > Thanks in advance, > > Julien > > -- > python -c "print ''.join([chr(154 - ord(c)) for c in '*9(9&(18%.9&1+,\'Z > (55l4('])" > > "When a distinguished but elderly scientist states that something is > possible, he is almost certainly right. When he states that something is > impossible, he is very probably wrong." (first law of AC Clarke) > -- > http://mail.python.org/mailman/listinfo/python-list > -- http://mail.python.org/mailman/listinfo/python-list
