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Graham Dumpleton
graham.dumpleton at gmail.com
Mon Jan 12 00:19:52 EST 2009
Now you do realise you don't need to convert 'import' to import_module() everywhere? The 'import' directive when used inside a file which was already managed by mod_python calls import_module() internally anyway. You just need to ensure you set mod_python's own module search path, ie. mod_python.importer.path Graham 2009/1/12 Tim Valenta <tonightslastsong at gmail.com>: > Okay, I think I'm on the same page as you now-- I've been playing > around with it and it seems that when I leave my PythonPath to find my > import modules, I definitely get no auto reloading goodness, while > when I specify the root path to find them as files, rather than as > modules (as explained in that documentation you linked to), things > seem to work as expected. > > I wasn't getting any warnings in my apache log, and after putting > together the details, I shouldn't be expecting any of that behavior > with two of the same module in memory. My issue seems to be simply in > avoiding letting my PythonPath find my code. > > Thank you much, > Tim > > On Sun, Jan 11, 2009 at 9:39 PM, Graham Dumpleton > <graham.dumpleton at gmail.com> wrote: >> 2009/1/12 Tim Valenta <tonightslastsong at gmail.com>: >>> Okay, that makes sense. My PythonPath system var definitely includes >>> my www directory. >> >> That in itself may not be enough to cause problem. You should actually >> see a warning in Apache error log complaining you have done this. That >> is, overlapped sys.path with directories that mod_python module >> importer uses. >> >> The real problem with doing this overlapping is that a module which >> wasn't one managed by mod_python, ie., standard Python module, imports >> something from the www directory, which also happens to be a handler >> module, there will actually be too copies in memory and so can give >> unexpected results. >> >> Graham >> >>> I had been using a forced path in my apache conf >>> file to point to '~', for simple reference for the time being. >>> >>> I think my problem is simply that the modules I'm trying to import >>> aren't 'candidates' for reloading. Other than that, all other modules >>> should already have been chained together with these >>> apache.load_module calls. My test case was pretty simple-- just two >>> scripts, the first loading the second. >>> >>> Tim >>> >>> On Sun, Jan 11, 2009 at 8:25 PM, Graham Dumpleton >>> <graham.dumpleton at gmail.com> wrote: >>>> 2009/1/12 Tim Valenta <tonightslastsong at gmail.com>: >>>>> Apologies for more trouble on the caching issue-- I've been adapting >>>>> some of my scripts over to this apache.load_module function, but I >>>>> don't think I'm seeing resolution to the issue. If I've read the >>>>> documentation properly, it seems that the PythonOption for >>>>> auto-reloading is set to On by default, so to be clear, I haven't put >>>>> a line for that in my httpd.conf file. Are there any other tricks, or >>>>> have I simply misread the documentation? I still have to restart the >>>>> Apache service in order to push the changes. >>>> >>>> Reloading does not work for any Python modules/packages installed in >>>> standard Python module search path. Thus, if you have set PythonPath >>>> to some directory where you store your modules, or if they are in >>>> system site-packages directory, they are not candidates for reloading. >>>> >>>> Where are the modules you are modifying and expecting to be reloading >>>> located? Is that location on sys.path, or have you explicitly setup >>>> mod_python module importer path to tell it where they are? >>>> >>>> From within running application, print out __name__ from the module >>>> you have loaded and are expecting to be reloadable, What is it? Does >>>> it look like a normal module name or something magic? >>>> >>>> How was that module imported? There needs to be a chain from >>>> mod_python handler for imports right down through to all modules you >>>> want reloadable. If there aren't, for example, you are using >>>> import_module() from a normal Python module which isn't a candidate >>>> for reloading, you will not see the depth checking for reloading >>>> occurring as you might expect. >>>> >>>> Graham >>>> >>>>> Tim >>>>> >>>>> On Sun, Jan 11, 2009 at 2:32 PM, Tim Valenta <tonightslastsong at gmail.com> wrote: >>>>>> Despite the jab at Windows, the site will be deployed on a Unix >>>>>> machine. I just prefer Windows for ease of use, especially since my >>>>>> wife has zero experience on a unix terminal or in the dearth of truly >>>>>> professional software found on the Unix/Linux platform. So yes, in >>>>>> the end it will be on a "real" operating system, But for now I'm >>>>>> willingly sticking to a more user-friendly environment for the simple >>>>>> folk. >>>>>> >>>>>> Given the characteristics of PHP that allow it to circumvent this >>>>>> caching stuff, I still think a nice little friendly red-flag reminder >>>>>> on the main mod_python tutorial should point out this limitation of an >>>>>> Apache module like this, for those of us like me, who would have gone >>>>>> many months more before having every accidentally found this manual >>>>>> import method. >>>>>> >>>>>> On Sun, Jan 11, 2009 at 2:23 PM, Graham Dumpleton >>>>>> <graham.dumpleton at gmail.com> wrote: >>>>>>> >>>>>>> 2009/1/12 Tim Valenta <tonightslastsong at gmail.com>: >>>>>>> >> Still not short enough, so much so I stopped part way through. >>>>>>> > >>>>>>> > And for that I apologize. I do appreciate the straight answer given, >>>>>>> > though I would appreciate much more the addition of that fact in some >>>>>>> > point-blank documentation that was easy to find. I have scoured the >>>>>>> > mod_python archives by search engine and came out utterly empty >>>>>>> > handed. I knew what the problem was, but I could find nothing to >>>>>>> > remedy the issue. I haven't encountered anything quite like this in >>>>>>> > my adventures with PHP, perl, or other similar scripting languages >>>>>>> > piloted by Apache. It raises a valid concern to which I ideally >>>>>>> > should have found answers very quickly. >>>>>>> > >>>>>>> > I hope this cures the subsequent issue given in the latter half of my message. >>>>>>> >>>>>>> PHP is specifically designed for web applications and it purposely >>>>>>> throws away all code at the end of each request and thus is reloading >>>>>>> it all on every request. Have a read of: >>>>>>> >>>>>>> http://blog.ianbicking.org/2008/01/12/what-php-deployment-gets-right/ >>>>>>> >>>>>>> I would be very surprised if mod_perl auto reloaded code as it is >>>>>>> similar to Python in that you are applying a non web language to the >>>>>>> web. Only way perl code would be reload is if you were running them as >>>>>>> CGI scripts. If you run Python as CGI scripts you will get reloading >>>>>>> as well, but as with anything CGI, much slower. >>>>>>> >>>>>>> BTW, maybe read: >>>>>>> >>>>>>> http://blog.dscpl.com.au/2008/12/using-modwsgi-when-developing-django.html >>>>>>> >>>>>>> For WSGI hosted Python web application, this provides auto reloading >>>>>>> on code changes. You do need to use a real operating system though, >>>>>>> and not Windows. >>>>>>> >>>>>>> Graham >>>>>>> >>>>>>> > Tim >>>>>>> > >>>>>>> > On Sat, Jan 10, 2009 at 10:23 PM, Graham Dumpleton >>>>>>> > <graham.dumpleton at gmail.com> wrote: >>>>>>> >> >>>>>>> >> 2009/1/11 Tim Valenta <tonightslastsong at gmail.com>: >>>>>>> >> > Hello all-- I've been experiencing a caching issue from the >>>>>>> >> > very beginning of my use of mod_python... It's been at least 2 months now, >>>>>>> >> > and I keep running into actual issues that prevent me from coding. >>>>>>> >> > I have a knack for over-explaining, so I'll try to keep this concise yet >>>>>>> >> > descriptive. >>>>>>> >> >>>>>>> >> Still not short enough, so much so I stopped part way through. >>>>>>> >> >>>>>>> >> The simple matter of it is that mod_python does not do deep checking >>>>>>> >> of code for changes, nor does it automatically restart the process >>>>>>> >> when code is changed. Thus the need to restart Apache when you make >>>>>>> >> code changes to anything imported from sys.path is expected and normal >>>>>>> >> behaviour. >>>>>>> >> >>>>>>> >> The only time any code is automatically reloaded is the direct code >>>>>>> >> files imported by mod_python using its own special module importer. >>>>>>> >> This is documented under 'import_module()' function in: >>>>>>> >> >>>>>>> >> http://www.modpython.org/live/current/doc-html/pyapi-apmeth.html >>>>>>> >> >>>>>>> >> Graham >>>>>>> >> >>>>>>> >> > I'm developing a site on my local machine, Windows Vista, using Apache 2.2.x >>>>>>> >> > and mod_python 3.3.1 . I'm a programmer for a living, and I'm not quick to >>>>>>> >> > point the finger at the language, *but* (you knew that was coming, eh?) I >>>>>>> >> > know my code isn't to blame for the issue: >>>>>>> >> > I write some basic code for an 'index.py' file, using the >>>>>>> >> > mod_python.publisher handler. 'index.py' includes other modules which I've >>>>>>> >> > coded from that same location, etc, etc. Nothing fancy. Any changes I make >>>>>>> >> > in the 'index.py' file will be reflected immediately on my local web server. >>>>>>> >> > On the other hand, any changes I make to the modules included via import >>>>>>> >> > from within 'index.py' are completely ignored by the web server. It took me >>>>>>> >> > a while to realize that my pages didn't reflect my code. I also discovered >>>>>>> >> > that the .pyc files had nothing to do with it. I finally just restarted the >>>>>>> >> > apache web service (which in fact runs as a service on my machine), and then >>>>>>> >> > my code finally gets pushed through to the web server. >>>>>>> >> > I've been looking around practically every other day for documentation on >>>>>>> >> > how to make apache/mod_python simply cut it out and stop caching my python >>>>>>> >> > code, but I've found nothing. You can imagine the annoyance this presents, >>>>>>> >> > since I have to restart my web server every single time I make even the >>>>>>> >> > slightest change to a 'utility.py' file, etc. >>>>>>> >> > I've been coping with the problem for a while now, but then I've found far >>>>>>> >> > more annoying issues recently. To abbreviate the problem into short terms, >>>>>>> >> > I've got a main module 'MAIN' which imports another module for a class >>>>>>> >> > 'CLASS'. CLASS also has a few imports, such as 'backend' stuff for >>>>>>> >> > interfacing with various databases, etc. We'll call the 'backend' module >>>>>>> >> > "BACKEND". Given the setup, any changes I make to CLASS or BACKEND require >>>>>>> >> > an apache restart in order to take effect. >>>>>>> >> > I have a function in CLASS which calls a function from it's imported BACKEND >>>>>>> >> > module. I tried adding a parameter to the BACKEND function in question, and >>>>>>> >> > properly passed said parameter while in CLASS, yet the mod_python debugger >>>>>>> >> > spits out an error about me having passed 3 arguments, when the BACKEND >>>>>>> >> > function takes exactly 2. This is outright false, since my function in >>>>>>> >> > BACKEND looks like: >>>>>>> >> > def getUsers(self, req, terms): >>>>>>> >> > >>>>>>> >> > and I'm calling it with >>>>>>> >> > self.backend.getUsers(self.req, search) >>>>>>> >> > >>>>>>> >> > In reality, my code dictates that I'm passing 3 (including the implicit >>>>>>> >> > 'self' argument), and BACKEND's 'getUsers' does in fact take exactly 3 >>>>>>> >> > arguments. Yet, the debugger is telling me that it takes only 2. >>>>>>> >> > I was trying to pass it 'req' because I wanted to investigate a little error >>>>>>> >> > in the code by printing something to the output HTML. So, my attempt is >>>>>>> >> > foiled, since somewhere something isn't being updated to what my most >>>>>>> >> > current code actually says. >>>>>>> >> > Just to test, I made the 'getUsers' function return immediately with a >>>>>>> >> > string of gibberish, like 'return "adsfasdfadsfa"'. this should make my >>>>>>> >> > other code spin wildly out of control and encounter errors, yet when I >>>>>>> >> > restart apache and test it... lo and behold, it's completely ignoring my >>>>>>> >> > goofy 'return' statement. The 'getUsers' function is still somehow >>>>>>> >> > returning valid data, as if the 'return' wasn't there at all! >>>>>>> >> > So then I tried causing actual syntax errors. The debugger caught this, >>>>>>> >> > much to my inner joy. So I tried causing a semantic error instead: >>>>>>> >> > referencing a non-existent attribute of a non-existent variable: >>>>>>> >> > madeUpVar.moo = 42 >>>>>>> >> > Syntactically, nothing wrong, but at run time it should most definitely >>>>>>> >> > encounter a NameError or something equally as realistic. But I restart >>>>>>> >> > apache, and... nothing. The line is completely ignored. >>>>>>> >> > Which leads me to believe that it's not actually being 'ignored' per se, but >>>>>>> >> > rather the code being compiled is not the same as the code in play within >>>>>>> >> > the web server. When I delete my .pyc files and restart apache and visit >>>>>>> >> > the URL that triggers my python code, my .py files are in fact being >>>>>>> >> > recompiled down to their byte code .pyc files. And clearly the interpreter >>>>>>> >> > is processing my code, since it flags me on improper syntax. Yet, no matter >>>>>>> >> > what kind of syntactically-sound nonsense I put into my code, the changes >>>>>>> >> > aren't being reflected in my web server. >>>>>>> >> > These problems come and go, and I've go better explanation than over zealous >>>>>>> >> > caching. I imagine that by tomorrow sometime when I start my computer up, >>>>>>> >> > the problem will have disappeared for the time being. >>>>>>> >> > I've cursed this computer up and down as I've tried to figure out ANYTHING >>>>>>> >> > that I can do to alleviate the issue, by to no avail. >>>>>>> >> > Anybody with counsel to spare my tired brain is welcome to share... >>>>>>> >> > _______________________________________________ >>>>>>> >> > Mod_python mailing list >>>>>>> >> > Mod_python at modpython.org >>>>>>> >> > http://mailman.modpython.org/mailman/listinfo/mod_python >>>>>>> >> > >>>>>>> >> > >>>>>>> > >>>>>> >>>>>> >>>>>> >>>>> _______________________________________________ >>>>> Mod_python mailing list >>>>> Mod_python at modpython.org >>>>> http://mailman.modpython.org/mailman/listinfo/mod_python >>>>> >>>> >>> >> >
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