On 4 October 2017 at 17:15, Ian Kelly <ian.g.ke...@gmail.com> wrote: > On Wed, Oct 4, 2017 at 9:08 AM, Steve D'Aprano > <steve+pyt...@pearwood.info> wrote: >> But in large projects, especially those where you cannot trust every module >> in >> the project to obey the naming convention, I can see that this lack might >> contribute to the perception, if not the fact, of Python being a bit too >> unsafe for big projects. We have read-only attributes in classes, but not >> read-only names in modules. That makes me a little bit sad. > > Which brings up the point that you can hack it in if you want it. > > $ cat demo.py > import sys > > class DemoModule: > @property > def foo(self): > return 42 > > sys.modules['demo'] = DemoModule() > > $ python3 -c 'import demo; print(demo.foo); demo.foo = 14' > 42 > Traceback (most recent call last): > File "<string>", line 1, in <module> > AttributeError: can't set attribute
I wonder - would the people who want "real constants" find the following confusing: >>> from demo import foo >>> foo = 14 >>> foo 14 It's fundamental to the way the import function works, and how names in Python behave, but I can see someone with a background in other languages with "real" constants thinking "but foo is a constant, and importing it stops it being a constant!" Paul -- https://mail.python.org/mailman/listinfo/python-list
