Re: [Tutor] simple question about scope SOLVED
Many thanks for this quick answer. I unfortunatly misread the tutorial (edx Course CS1301xII, Computing in Python II: Control Structures) concerning scope insofar as a NameError arises if a variable is accessed which was not created inside the control structure. Marcus. -Ursprüngliche Nachricht- Von: Tutor [mailto:tutor-bounces+marcus.luetolf=bluewin...@python.org] Im Auftrag von Alan Gauld via Tutor Gesendet: Samstag, 18. Mai 2019 12:34 An: tutor@python.org Betreff: Re: [Tutor] simple question about scope On 18/05/2019 09:20, marcus lütolf wrote: > in learning the principles of Python I came across scope in the > control structure's section. > There I read the notion that variables createted inside a control > structute can't be seen or accessed from outside that structure, > Python would raise a Name Error. I don't know which tutorial you are reading but that's just wrong. Names created inside functions are local to that function. Names created inside a module are local to that module (and rather confusingly referred to as global scope) Names created inside a class are local to that class. Names created inside a generator expression are local to that expression. That's pretty much all you need to know about python scoping. > However in for loops - also control structures - like in this simple > example: Control structures like for/while/if-else etc have no influence no name visibility. -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ http://www.amazon.com/author/alan_gauld Follow my photo-blog on Flickr at: http://www.flickr.com/photos/alangauldphotos ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor --- Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft. https://www.avast.com/antivirus ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] simple question about scope
On 5/18/19 2:20 AM, marcus lütolf wrote: > Dear experts > > in learning the principles of Python I came across scope in the > control structure's section. > There I read the notion that variables createted inside a > control structute can't be seen or accessed from outside that > structure, Python would raise a Name Error. > > However in for loops - also control structures - like in this > simple example: > > for i in range(1,11): > sum = 0 > sum += i > print(sum) > > the print function "returns" the last number of range as > value of the variable sum created inside this for loop. > It should have raised a Name Error instead. > Could somebody please explain this discrepancy? in addition to Alan's comment, in your loop you are resetting sum to zero each time through, which is why at the end of the loop sum is the same as the finishing value of i, not the sum of the values... ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] simple question about scope
On 18/05/2019 09:20, marcus lütolf wrote: > in learning the principles of Python I came across scope in the > control structure's section. > There I read the notion that variables createted inside a > control structute can't be seen or accessed from outside that > structure, Python would raise a Name Error. I don't know which tutorial you are reading but that's just wrong. Names created inside functions are local to that function. Names created inside a module are local to that module (and rather confusingly referred to as global scope) Names created inside a class are local to that class. Names created inside a generator expression are local to that expression. That's pretty much all you need to know about python scoping. > However in for loops - also control structures - like in this > simple example: Control structures like for/while/if-else etc have no influence no name visibility. -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ http://www.amazon.com/author/alan_gauld Follow my photo-blog on Flickr at: http://www.flickr.com/photos/alangauldphotos ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
