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Tim Valenta
tonightslastsong at gmail.com
Tue Jan 13 00:25:46 EST 2009
Ah, I've seemed to produce the most lethal of the side effects: Upon making B use 'import_module()', while C is in a subdirectory, C is completely immune to changes. It claims it finds C now, but C is completely overlooked in execution. C is supposed to write out text to my browser, yet nothing shows up at all. I imagine an empty version of C is cached somewhere, and restarting Apache does nothing to solve the issue. C is still empty as far as Apache knows. On Mon, Jan 12, 2009 at 10:17 PM, Tim Valenta <tonightslastsong at gmail.com> wrote: >> You just need to ensure you set mod_python's own module search path, >> ie. mod_python.importer.path > > And yet, as I've now removed my www directory from my PythonPath, I > actually get limited functionality out of the mod_python imports. > I've got my apache conf file globally applying the option: > > PythonOption mod_python.importer.path "['~']" > Also have tried using an absolute path, which is producing the same > functionality: > PythonOption mod_python.importer.path "['V:/www/']" > > My main module ('A') is requested by Apache in my browser, which uses > import_module to find and import file B. File B is in the same > directory as A, and they only way it was found was through my apache > conf noted above. This part works just fine, but two cases develop > from here: > > 1) If I use module B to import a third module 'C', I can't seem to > make it find module C if it's in a subdirectory. For instance, doing > either 'import subDirectory.moduleC' or doing > 'apache.import_module("subDirectory/moduleC")' results in a failure to > find the module. Note that in this case of subdirectories, I'm > intentionally avoiding absolute paths to reach my modules. I only > want to get absolute in my Apache conf. On the flip side, if module C > is in the same local directory as A and B, then mod_python finds > module C just fine. > > 2 ) If I place C in the same directory as A and B, so that mod_python > finds it, I tried using the natural Python 'import' keyword in B to > import C. According to what I understand, this should be fine for > auto-reloading, since A imports B via import_module, and so then B can > use either importing strategy to get C in the picture because > mod_python uses import_module behind the scenes anyway. In this > setup, my caching issue remains, and changes to C are definitely not > reflected in apache until a server restart. Again note that it > doesn't matter if I make B use the 'import' keyword or the > apache.import_module() method. Both result in failure to reload. > > I can't seem to diagnose what's even wrong, since the only reason > module A, B, or C is being found in the first place is because of my > importer.path variable is set in httpd.conf. I've been using > practically empty files to test this. Each file contains no more than > 5 lines to get the modules imported and then to write out a > confirmation to the screen that it worked. > > Wisdom to offer? > >> 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 > -- "Thanksgiving Dinner sent you a message." "If you are not a member, you need to join us." 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