Running simultaneuos FOR loops
i have to implement the below line in one of my code: for p in sorted(segments.iterkeys()) and for k in sorted(class_count.iterkeys()) and for j in sorted(pixel_count.iterkeys()): Its giving me a syntax error which is obvious, but how can I make all three for loop run simultaneously or any other way to do this simultaneous work ??? -- http://mail.python.org/mailman/listinfo/python-list
Re: Running simultaneuos FOR loops
On Tue, Apr 23, 2013 at 4:40 PM, inshu chauhan insidesh...@gmail.com wrote: i have to implement the below line in one of my code: for p in sorted(segments.iterkeys()) and for k in sorted(class_count.iterkeys()) and for j in sorted(pixel_count.iterkeys()): Its giving me a syntax error which is obvious, but how can I make all three for loop run simultaneously or any other way to do this simultaneous work ??? Define simultaneously. Do the three dictionaries have the same number of keys? If so, look up zip() or itertools.izip; if not, you may have to more clearly define simultaneous. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: Running simultaneuos FOR loops
Yes Simultaneously means all three running at the same time, I looked up zip just now, but will it not disturb my dictionaries ? And yes the dictionaries have same number of keys. thanks On Tue, Apr 23, 2013 at 12:16 PM, Chris Angelico ros...@gmail.com wrote: On Tue, Apr 23, 2013 at 4:40 PM, inshu chauhan insidesh...@gmail.com wrote: i have to implement the below line in one of my code: for p in sorted(segments.iterkeys()) and for k in sorted(class_count.iterkeys()) and for j in sorted(pixel_count.iterkeys()): Its giving me a syntax error which is obvious, but how can I make all three for loop run simultaneously or any other way to do this simultaneous work ??? Define simultaneously. Do the three dictionaries have the same number of keys? If so, look up zip() or itertools.izip; if not, you may have to more clearly define simultaneous. ChrisA -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: Running simultaneuos FOR loops
On 04/22/2013 11:40 PM, inshu chauhan wrote: i have to implement the below line in one of my code: for p in sorted(segments.iterkeys()) and for k in sorted(class_count.iterkeys()) and for j in sorted(pixel_count.iterkeys()): Its giving me a syntax error which is obvious, but how can I make all three for loop run simultaneously or any other way to do this simultaneous work ??? Be clearer about the problem please. Do you wish to produce a loop that: On pass 1, each of p,k, and t hold the first item of their respective lists, and on pass 2, each of p,k, and t hold the second item of their respective lists, and so on until one (or all) lists run out? If that is what you want, then check out the zip builtin function. But also consider this: Do you care what happens if one list runs out before the others? Or is it something else you want? Perhaps nested loops? for p in sorted(segments.iterkeys()): for k in sorted(class_count.iterkeys()): for j in sorted(pixel_count.iterkeys()): # This will be run with all possible combinations of p,k, and t. Gary Herron -- http://mail.python.org/mailman/listinfo/python-list
Re: Running simultaneuos FOR loops
zip isn't doing the required On Tue, Apr 23, 2013 at 12:28 PM, inshu chauhan insidesh...@gmail.comwrote: Yes Simultaneously means all three running at the same time, I looked up zip just now, but will it not disturb my dictionaries ? And yes the dictionaries have same number of keys. thanks On Tue, Apr 23, 2013 at 12:16 PM, Chris Angelico ros...@gmail.com wrote: On Tue, Apr 23, 2013 at 4:40 PM, inshu chauhan insidesh...@gmail.com wrote: i have to implement the below line in one of my code: for p in sorted(segments.iterkeys()) and for k in sorted(class_count.iterkeys()) and for j in sorted(pixel_count.iterkeys()): Its giving me a syntax error which is obvious, but how can I make all three for loop run simultaneously or any other way to do this simultaneous work ??? Define simultaneously. Do the three dictionaries have the same number of keys? If so, look up zip() or itertools.izip; if not, you may have to more clearly define simultaneous. ChrisA -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: Running simultaneuos FOR loops
Thanks Gary. Be clearer about the problem please. Do you wish to produce a loop that: On pass 1, each of p,k, and t hold the first item of their respective lists, and on pass 2, each of p,k, and t hold the second item of their respective lists, and so on until one (or all) lists run out? Yes this is excatly what I want each loop holds the first item on each pass. If that is what you want, then check out the zip builtin function. But also consider this: Do you care what happens if one list runs out before the others? Yes, but all dictionaries have same number of items. Or is it something else you want? Perhaps nested loops? for p in sorted(segments.iterkeys()): for k in sorted(class_count.iterkeys()): for j in sorted(pixel_count.iterkeys()): # This will be run with all possible combinations of p,k, and t No, I know about nested loops but I dont want that because all the loops have same number of items, inner loops will run out earlier. Gary Herron -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: Running simultaneuos FOR loops
This statement is giving me the following error Statement: for p, k, j in zip(sorted(segments.iterkeys(), class_count.iterkeys(), pixel_count.iterkeys())): Error: Traceback (most recent call last): File C:\Users\inshu\Desktop\Training_segs_trial2.py, line 170, in module access_segments(segimage, data) File C:\Users\inshu\Desktop\Training_segs_trial2.py, line 147, in access_segments for p, k, j in zip(sorted(segments.iterkeys(), class_count.iterkeys(), pixel_count.iterkeys())): TypeError: 'dictionary-keyiterator' object is not callable On Tue, Apr 23, 2013 at 12:33 PM, inshu chauhan insidesh...@gmail.comwrote: zip isn't doing the required On Tue, Apr 23, 2013 at 12:28 PM, inshu chauhan insidesh...@gmail.comwrote: Yes Simultaneously means all three running at the same time, I looked up zip just now, but will it not disturb my dictionaries ? And yes the dictionaries have same number of keys. thanks On Tue, Apr 23, 2013 at 12:16 PM, Chris Angelico ros...@gmail.comwrote: On Tue, Apr 23, 2013 at 4:40 PM, inshu chauhan insidesh...@gmail.com wrote: i have to implement the below line in one of my code: for p in sorted(segments.iterkeys()) and for k in sorted(class_count.iterkeys()) and for j in sorted(pixel_count.iterkeys()): Its giving me a syntax error which is obvious, but how can I make all three for loop run simultaneously or any other way to do this simultaneous work ??? Define simultaneously. Do the three dictionaries have the same number of keys? If so, look up zip() or itertools.izip; if not, you may have to more clearly define simultaneous. ChrisA -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: Running simultaneuos FOR loops
On Tue, Apr 23, 2013 at 5:13 PM, inshu chauhan insidesh...@gmail.com wrote: This statement is giving me the following error Statement: for p, k, j in zip(sorted(segments.iterkeys(), class_count.iterkeys(), pixel_count.iterkeys())): You probably want to sort them separately. By the way, using iterkeys() isn't going to do much for you, since you're sorting them; you need to see all the keys to sort them. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: Running simultaneuos FOR loops
Am 23.04.2013 09:13, schrieb inshu chauhan: This statement is giving me the following error Statement: for p, k, j in zip(sorted(segments.iterkeys(), class_count.iterkeys(), pixel_count.iterkeys())): Error: Traceback (most recent call last): File C:\Users\inshu\Desktop\Training_segs_trial2.py, line 170, in module access_segments(segimage, data) File C:\Users\inshu\Desktop\Training_segs_trial2.py, line 147, in access_segments for p, k, j in zip(sorted(segments.iterkeys(), class_count.iterkeys(), pixel_count.iterkeys())): TypeError: 'dictionary-keyiterator' object is not callable Which of the statements on that line causes the error? I guess asking yourself that question will lead you to the answer already! ;) Any reason you quoted your own and several others' messages, am I missing some reference there? Good luck! Uli -- http://mail.python.org/mailman/listinfo/python-list
Re: Running simultaneuos FOR loops
inshu chauhan insidesh...@gmail.com wrote: This statement is giving me the following error Statement: for p, k, j in zip(sorted(segments.iterkeys(), class_count.iterkeys(), pixel_count.iterkeys())): Error: Traceback (most recent call last): File C:\Users\inshu\Desktop\Training_segs_trial2.py, line 170, in module access_segments(segimage, data) File C:\Users\inshu\Desktop\Training_segs_trial2.py, line 147, in access_segments for p, k, j in zip(sorted(segments.iterkeys(), class_count.iterkeys(), pixel_count.iterkeys())): TypeError: 'dictionary-keyiterator' object is not callable The second argument to `sorted()` is a comparison or key function, if you want to sort all three key lists you need to sort them separately. Try: for p, k, j in zip(sorted(segments), sorted(class_count), sorted(pixel_count)): also you don't need to call the `iterkeys()` method as you need them all to sort and just treating the dict as a sequence will do the right thing. -- Duncan Booth http://kupuguy.blogspot.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Running simultaneuos FOR loops
On 04/23/2013 02:58 AM, inshu chauhan wrote: Yes Simultaneously means all three running at the same time, I looked up zip just now, but will it not disturb my dictionaries ? And yes the dictionaries have same number of keys. More crucially, do all the dictionaries have the *same* keys? If so, then all the zip logic is unnecessary, as the p, k, and j values will always be identical. If they have the same keys, then do something like: for key in sorted(segments): val1 = segments[key] val2 = class_count[key] val3 = pixel_count[key] ... do something with those values If any of the keys is missing in one of the other dicts, you'll get an exception. You might also want to do a check of the size of the 3 dicts, just in case. -- DaveA -- http://mail.python.org/mailman/listinfo/python-list
