I thought I'd 'got' globals but...
I thought I had 'got' globals but this one seems strange. I want my example function 'doIt' to use and optionally modify a module variable 'gname', so I declare 'global gname' in the function, but when modified it doesn't stay modified. gname = 'Sue' def doIt(name = gname): global gname gname = name print 'doIt name', name, 'gname', gname print 'start gname', gname doIt() doIt(name='Lisa') doIt() print 'finish gname', gname gives... start gname Sue doIt name Sue gname Sue doIt name Lisa gname Lisa doIt name Sue gname Sue finish gname Sue The variable gname has reverted back to value 'Sue' Curiously though, without the third doIt() call, it works... print 'start gname', gname doIt() doIt(name='Lisa') #doIt() print 'finish gname', gname gives... start gname Sue doIt name Sue gname Sue doIt name Lisa gname Lisa finish gname Lisa The variable gname has been modified to 'Lisa' Any ideas how I can make the 'Lisa' assignment permanent forever in 2nd doIt? Thanks (Note. Contrived example substitutes for a web-type app, where, if the page is called without arguments then it displays the global defaults. If the page is called with form arguments then it should be able to change the global defaults) -- http://mail.python.org/mailman/listinfo/python-list
Re: I thought I'd 'got' globals but...
Bruno Desthuilliers wrote: > def doIt(name=None): > global gname > if name is None: > name = gname > else: > gname = name > Thanks Bruno, works a treat... -- http://mail.python.org/mailman/listinfo/python-list
Re: I thought I'd 'got' globals but...
Bruno Desthuilliers wrote: > meridian wrote: > > Bruno Desthuilliers wrote: > > > >>def doIt(name=None): > >> global gname > >> if name is None: > >>name = gname > >> else: > >>gname = name > >> > > > > > > Thanks Bruno, works a treat... > > > But still very probably a bad idea. > Ok, my curiosity is pique'd - is there a better way to hold my app/module globals? I must say I'd prefer not to write global in every function, for every global var I need. Maybe there's a simpler way to structure?... by a global class or something? Cheers Steve -- http://mail.python.org/mailman/listinfo/python-list
Re: I thought I'd 'got' globals but...
You mentioned earlier that "Modifying globals from within a function is usually a very bad idea." Most of my app consists of functions or class/object functions, that's all I do in OOP. Did you mean that modifying globals from anywhere is bad? or globals are bad? or don't code using methods/functions? not sure... -- http://mail.python.org/mailman/listinfo/python-list
Re: I thought I'd 'got' globals but...
Thanks Bruno. Not only do you give solutions to my problem but also throw in great MVC tutorials too. You're a gent. I'm using controller -> A CherryPy app views -> Cheetah Templating for the html & data model -> mostly SQLite DB using pysqlite also Config It's only a desk-web app for single-user, so no concurrency issues. However, taking on board your advice to avoid globals, I've now realised that the info that I need to retain between pages can simply be session information (for the only user) that can be initialised at startup from the config. So I'm looking at just storing it all in the cherrypy.session ram vs using python globals. Thanks again & Regards Steve -- http://mail.python.org/mailman/listinfo/python-list
slices - handy summary
If, like me, you're always forgetting which way around your list/seq slices need to go then worry no more. Just put my handy "slice lookupper" (TM) ) on a (large!) PostIt beside your screen and, Hey Presto! no more tediously typing a 1-9 seq into your interpreter and then getting a slice just to check what you get.. (Yes you. You know you do that !) ...Cheers Steve x = '0123456789' x[-10: ] 0123456789 x[ 0: ] x[ -9: ] 123456789 x[ 1: ] x[ -8: ] 23456789 x[ 2: ] x[ -7: ] 3456789x[ 3: ] x[ -6: ] 456789 x[ 4: ] x[ -5: ] 56789 x[ 5: ] x[ -4: ] 6789 x[ 6: ] x[ -3: ] 789x[ 7: ] x[ -2: ] 89 x[ 8: ] x[ -1: ] 9 x[ 9: ] x[ :-9 ] 0 x[ :1 ] x[ :-8 ] 01 x[ :2 ] x[ :-7 ] 012x[ :3 ] x[ :-6 ] 0123 x[ :4 ] x[ :-5 ] 01234 x[ :5 ] x[ :-4 ] 012345 x[ :6 ] x[ :-3 ] 0123456x[ :7 ] x[ :-2 ] 01234567 x[ :8 ] x[ :-1 ] 012345678 x[ :9 ] 0123456789 x[ :10 ] -- http://mail.python.org/mailman/listinfo/python-list
