Re: persistant gloabl vars (very newbie) ?
Erik Johnson wrote: but it's still not quit handy # initialization file (init1.py) import time; xx = 44 # main file was print xx x=time.time() # main file should become print init1.xx x=init1.time.time() so even for the standard functions like time I've to include the preceeding module init1 :-( Ummm... does this help? /src/python/Foo cat init.py #! /usr/local/bin/python from time import time xx = 44 /src/python/Foo python Python 2.3.4 (#1, Feb 7 2005, 15:50:45) [GCC 3.3.4 (pre 3.3.5 20040809)] on linux2 Type help, copyright, credits or license for more information. from init import * dir() ['__builtins__', '__doc__', '__file__', '__name__', 'time', 'xx'] xx 44 time built-in function time time() 1167262478.6845641 xx = 42 # this does not change the init module's value! import init init.xx 44 As Piet points out, you get a copy of variables defined in a module when using the from module import * syntax (as is demonstrated by the assignment above). (And I stand corrected on the notion that you could execute from module import * in other than module level scope.) If it is your intention to use those variables defined in init to communicate with other modules making the same sort of import, then you probably don't want to use from module import * syntax. In that case, you can import just the module, and make assignments into that module's namespace. (e.g., init.xx = 3) If all you care about is getting some stuff into your global namespace in a convenient and repeatable way, then I think what I showed both above and originally is fine. thanks Erik, I think I'm slowly getting the picture: always use import, which is the most unambiguous approach. Life is sometimes difficult for a MatLab user, see my next post ;-) Stef -- http://mail.python.org/mailman/listinfo/python-list
persistant gloabl vars (very newbie) ?
hi all, I'm investigating the possibilities to replace MatLab with Python (+NumPy +SciPy). I'm a very newbie, I just typed my first characters and calculated the sum of 2 and 3 in Python. My application is a Delphi program, for data-acquisition and real-time data analysis. The real-time analysis is done with MatLab, embedded through a OLE coupling. I already found PythonforDelphi which probably helps a lot to make the first steps. But I'm now stumbled about something very basic, which I don't understand. The problem might be due to the IDE I use (PyScripter), but I tried several and they all behave the same. And I expect that the observed behaviour might be very important notch in my final application (blockwise, real time interaction). In MatLab I declare a workspace, in which each variable I declare is automatically global, and can be reached from all views, i.e. from the command line interpreter as well as form the OLE environment, no matter where they are declared. I try to do something similar in Python: - I want to run an initialization part just once - I want to run some testcode often and interactively So the most simple example: #Initialization import time; A = 5; #code under test x=time.time(); # do something time consuming print 1000*(time.time()-x); Now if I run the initialization part, manual line by line in the command line interpreter, I can run the code under test as often as I want. My real initilization code is much larger and therefor very clumsy to run line by line in the command line interpreter. Is there a way to run the initialization code from a script(file) once, to achieve the same effect ? thanks, Stef Mientki -- http://mail.python.org/mailman/listinfo/python-list
Re: persistant gloabl vars (very newbie) ?
Stef Mientki [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Is there a way to run the initialization code from a script(file) once, to achieve the same effect ? Certainly. This is what Python modules are all about. You should probably read up on those a bit here: http://docs.python.org/tut/node8.html But briefly, probably what you want to do is put some code in a file, say init.py: # init.py X = 3 Y = 5 # A bunch of other stuff And then in your main program, execute from init import * That will take all the module-scoped variables defined in init.py and place them in the namespace of the import statement (whcih could be global, the interactive interpreter, or otherwise) See also the 'global' statement as it relates to modifying global variables in an inner scope. Good luck, -ej -- http://mail.python.org/mailman/listinfo/python-list
Re: persistant gloabl vars (very newbie) ?
Erik Johnson ej at wellkeeper dot com (EJ) wrote: EJ But briefly, probably what you want to do is put some code in a file, say EJ init.py: EJ # init.py EJ X = 3 EJ Y = 5 EJ # A bunch of other stuff EJ And then in your main program, execute EJ from init import * EJ That will take all the module-scoped variables defined in init.py and place EJ them in the namespace of the import statement (whcih could be global, the EJ interactive interpreter, or otherwise) This way of saying it is slightly wrong or misleading. It does not place the global variables of init.py in the importing module in the same way as most other programming languages use this concept. Rather it makes new bindings in the importing module with the same names and the same values as in the original module. So they are new variables with the same values. If in the importing module e.g. you say X = 4, this will change the value of X in the importing module, but not in the init module, nor in any other module that has done 'from init import *'. If you want that kind of behaviour it is better to use: 'import init' and refer to the variables as init.X and init.Y so that you can change them. Whether that is a good idea is another matter. There are other reasons for not using the from init import * form, as you might overwrite bindings in the module in an unforseen way. from init import X,Y explicitely is probably safer. And, by the way, from init import * can only be used at module level, not in inner namespaces. -- Piet van Oostrum [EMAIL PROTECTED] URL: http://www.cs.uu.nl/~piet [PGP 8DAE142BE17999C4] Private email: [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
Re: persistant gloabl vars (very newbie) ?
other module that has done 'from init import *'. If you want that kind of behaviour it is better to use: 'import init' and refer to the variables as init.X and init.Y so that you can change them. Whether that is a good idea is another matter. There are other reasons for not using the from init import * form, as you might overwrite bindings in the module in an unforseen way. from init import X,Y explicitely is probably safer. And, by the way, from init import * can only be used at module level, not in inner namespaces. thank you guys, but it's still not quit handy # initialization file (init1.py) import time; xx = 44 # main file was print xx x=time.time() # main file should become print init1.xx x=init1.time.time() so even for the standard functions like time I've to include the preceeding module init1 :-( cheers, Stef Mientki -- http://mail.python.org/mailman/listinfo/python-list
Re: persistant gloabl vars (very newbie) ?
but it's still not quit handy # initialization file (init1.py) import time; xx = 44 # main file was print xx x=time.time() # main file should become print init1.xx x=init1.time.time() so even for the standard functions like time I've to include the preceeding module init1 :-( Ummm... does this help? /src/python/Foo cat init.py #! /usr/local/bin/python from time import time xx = 44 /src/python/Foo python Python 2.3.4 (#1, Feb 7 2005, 15:50:45) [GCC 3.3.4 (pre 3.3.5 20040809)] on linux2 Type help, copyright, credits or license for more information. from init import * dir() ['__builtins__', '__doc__', '__file__', '__name__', 'time', 'xx'] xx 44 time built-in function time time() 1167262478.6845641 xx = 42 # this does not change the init module's value! import init init.xx 44 As Piet points out, you get a copy of variables defined in a module when using the from module import * syntax (as is demonstrated by the assignment above). (And I stand corrected on the notion that you could execute from module import * in other than module level scope.) If it is your intention to use those variables defined in init to communicate with other modules making the same sort of import, then you probably don't want to use from module import * syntax. In that case, you can import just the module, and make assignments into that module's namespace. (e.g., init.xx = 3) If all you care about is getting some stuff into your global namespace in a convenient and repeatable way, then I think what I showed both above and originally is fine. -ej -- http://mail.python.org/mailman/listinfo/python-list
